Aaron turned the computer on and looked for Susanna. She had disappeared; had been absent for weeks now. Of course she could have gone on holidays. Skiing. The people at Katherine’s work went skiing quite often. They took their expensive goosedown coats and bought single-purpose equipment and went off to Japan or New Zealand or Switzerland for a week or two. Perhaps Susanna would turn up again tonight. Maybe tomorrow. For now she was just a name on the screen with a little grey box beside it.

Aaron knew he was an optimist. When he was a child he had believed in Santa Claus for far too long. Even when the other kids at school had already stepped through to the world of cynicism he was still writing his Christmas letter and letting Katherine help him glue sequins to his felt stocking. Katherine, helping his parents in their seemingly innocent lie. His tears when he found out were all the more desolate because it was Katherine who had colluded with his parents. She sobbed alongside him, clutching his shoulders; he remembered the words of more than thirty years ago as clearly as if she had said them this morning. I didn’t want to destroy your dreams.

He looked through his Skype list and saw the name Rachel, lit up with a green glow of possibility. He closed his eyes and felt that same creeping hope, that Christmas wishing. Maybe his loneliness would conjure her like a genie. His Susanna, a woman he had never even seen because she never turned her webcam on. For all he knew she might be a man. She could be anywhere in the world. She could be a Maori man, a German woman, a matron with arms like a sailor or some balding ex-criminal with a teardrop tattoo.

It didn’t matter really. Whoever she or he was, Susanna had been close to him when no one else except Katherine had really spoken to him in years.

When the call came in, the tinny sound of it, Aaron twitched in his chair. He opened his eyes and saw the name Rachel leap up onto the screen. He hadn’t really expected Rachel to call him. She’d said she would, but he discounted every assurance made on the internet. It was a place where you need not be a liar in real life to reinvent yourself, polish the edges of your story. Change your identity one sentence at a time.

He’d thought he had seen the last of the zoo girls but here they were again, or Rachel anyway, calling him up at the agreed time. It was almost disappointing to see the name attached to the call. The zoophiles. Aaron wasn’t sure he could get very excited about their strange kind of bestial sex. Was the idea of two girls lying with an animal even remotely sexy?

He supposed he could disconnect the call if it was too much for him. That little boy who was so excited about Santa Claus had a sister who would protect him from his own expectations. Now, Aaron. Don’t be disappointed if Santa is just too busy to visit our house tonight. He has hundreds of other girls and boys who don’t have any toys to play with at all. At least we have each other. You have to try not to be too excited. Go to sleep, and I will be right here on the other side of the wall. Tap if you need to know I’m there, and I will tap right back.

Aaron’s cursor hovered over the jumping icon.

At one time, every incoming Skype was Susanna. It was her humour he missed most, the comfortable nightly banter. And although he had never seen her face, he missed his idea of her. She wore glasses in the fantasy he had constructed, she was studious but pretty. A blonde, he thought, because Katherine was a brunette, the most beautiful dark-haired beauty. Sleeping beauty. Heavy-lidded and forever exhausted from her day, tumbling into the kind of sleep that a pill might bring to other women. The all-encompassing sleep that hinted at astral travel, other worldliness, fairytale princesses.

Not a brunette, then. He had made Susanna into a cheerful, studious blonde, a literature student. She certainly was well read. She shared this quality with Katherine, they were both good readers. Aaron struggled to keep up, ordering books that one woman or the other had recommended, asking Katherine to check them out of the library for him.

He suspected Katherine hated the library. Once it had been a job that excited her. On her first day she had raced home to tell him that at last she could spend all day surrounded by her favourite books. She brought them home, great towering piles of them, devouring them greedily one after another, but her enthusiastic reading had slowed as the exhaustion of the daily grind set in.

Now she mostly read just one or two pages, struggling to stay upright on the couch beside him, her head dropping onto his shoulder, the fragrant waterfall of hair tickling his cheek as she slipped into her enchanted sleep.

She usually rose before dawn. He would hear her soft clatter start up in the kitchen so early that only moonlight poured through the gap between the curtains. Sometimes, when he cuddled with her on the couch straight after dinner, she would talk with him in low whispers, kissing his chest and snuggling into his arms. After a time he would feel her grow heavier, as if sleep brought him more of her physical body even as it made off with her soul.

He remembered the day Susanna stopped calling him. It was just like that, a sudden cessation of contact. He felt as if he had come home to an empty house, any trace of her gone in an instant. There had been no hint that she was losing interest in their internet play, she had seemed as ardent a lover from one moment to the next. He sat puzzled, a little hurt, waiting for her call for almost a week, too shaken by the loss to call up the usual parade of faceless torsos.

After a second week of silence he dragged himself back there, to the safe terrain of the chat sites. Men mostly, but sometimes women too; bodies in various shapes and sizes, some beautiful, some not; all prepared to masturbate for him with little provocation; each one a warm human presence located elsewhere. It filled in the hours while Katherine slept.

He closed the bedroom door. Katherine lay like her fairytale alter ego on the crisp cotton sheets of their bed, her brown hair glowing red in the pool of the bedside light. He blew her a kiss from the doorway and she smiled in her sleep as if the little dart of love had landed on her forehead.

He had always loved her—from the moment he was born, although he didn’t remember it at all. Their parents told them that he had reached out with his new-formed fist and grabbed Katherine’s chubby toddler arm, his eyes still without focus, his mouth forming its first ever grin at the sightless touch, the hiccupping laughter surprising everybody in the room.

He had bonded with her from that first moment and from then on every new and wonderful thing the world gave to him he would grab and drag—crawling first, then taking shaky steps, then finally running—to bring the new treasure to his sister, seeking her approval of every new discovery.

They were so close that in the years before Katherine shot up in height, most people took them to be twins. She grew to be a willowy beauty, but Aaron still remembered her as the boyish kid of their childhood, whispering her secrets to him. Running through the scrap of bushland behind their suburban house, daring him to follow.

One Christmas when he was nine and Katherine was still a twelve-year-old tomboy, their parents gave them matching prints of the Rubens painting Romulus and Remus, the wild and naked children suckling on the tit of a she-wolf. Even now, Rubens was one of Aaron’s favourite classical artists, a passion he used to share with the elusive Susanna when they were still nightly companions.

The zoo girls had a Rubens print on their wall too. He had glimpsed it through their webcam while the pair were demonstrating their pantomime of bestial sex, the talkative girl mounting the quiet girl as if she were a dog, panting and humping and nipping at her back. The laptop had been disturbed during their exuberant display and as it tipped he glimpsed the painting hanging above their bed. Leda and the Swan, the Rubens version, the one he and Susanna loved the most. It was only because of this painting that Aaron Fitzgerald had given them his Skype address.

They worried him, these girls. Their naïve brazenness aroused not only his desire, but a protective impulse. Some other men he had met on the internet would take advantage of their openness. Some men would film them secretly and post the video for profit. He was tempted, of course, to film this session for his own pleasure. How often would he get to see two girls cavorting with a dog? He could play the footage back if it aroused him; he could show it to Susanna. If she ever returned.

He watched the flashing of the Skype call waiting to be put through. No, he would not record this. He never had and probably never would record anything people showed him on the internet. He knew it was ridiculous, but part of him imagined that if he respected other people’s privacy they might possibly respect his own.

Aaron Fitzgerald accepted the call, raised his glass of scotch to his lips and rattled the ice.

Are we on the farm now? he tapped on the keyboard. After a second a figure emerged from the dark jumble of shapes on the screen. It was the chatty one, Rachel. The pretty one sat behind her, rubbing the short clean coat of the kelpie in her lap.

‘You’re not going to turn your webcam on?’ Rachel leaned towards the screen. She was wearing a dressing gown and the neck gaped a little as she bent forward. Aaron could see the soft curve of one of her breasts, that slight delay of image as she moved in discrete frozen moments. There was a strange excitement in watching this staccato hide-and-reveal, the thrill of a security camera, an element of covert espionage.

Aaron felt the familiar stirring in his groin. These relative strangers about to reveal their bodies to him on the screen.

No, Aaron typed, I don’t turn my webcam on anymore. I am afraid you have to take me (as it were) in the dark.

‘How do we know there isn’t a group of you, sitting out there watching us? Jerking off?’

I assure you there is only one of me and I also assure you I will be touching myself as I watch you. It turns me on to think that I will see you with your friend there. This is your friend?

He watched as the prettier one leant to kiss the kelpie on his neck. The dog turned over to let her scratch his belly and Aaron was treated to a display of the dog’s excitement as the woman scratched and rubbed the soft fur between its legs.

‘Sure. That’s my friend, but how do we know that you are even a girl? You say you are a zoophile but what’s to prove that?’ The chatty one moved back to sit on the couch beside the pretty girl and the kelpie yipped and flipped over onto his stomach, licking the woman’s chin and beginning to rub his hips against her leg.

You can’t know for sure, but you can choose. The internet is like that. You can close this connection at any time. Or you can take your clothes off and let me watch as that puppy mounts you, and enjoy that kind of exhibitionism for what it is.

The chatty one stood and dropped her dressing gown. Nice breasts, thickening waist…but none of that mattered. The mistake women often made, Aaron thought, was to expect that men watching them would be judging their bodies as they judged themselves. Very few women showed themselves on their webcams, and although Aaron found a certain pleasure in watching the men bring themselves to orgasm on the screen, his preference had always been for women; he would appreciate them for what they were.

He felt his excitement mounting as the chatty one— Rachel; he would need to remember their names—Rachel turned to her friend. The kelpie leaped onto the ground and jumped up at her hips, its penis stiff and red, its teeth nipping at air. He watched as she lifted her friend—Leda, that was easier to remember—by the hands and unbuttoned her housecoat. The body revealed was almost as slim and taut as Katherine’s body; she looked like Katherine, this one, a thick head of curled brown hair, a small waist flaring to more generous hips, a coy smile. Aaron was surprised that even amid his online infidelity he became more excited by someone who looked like his lover.

He unzipped his pants and took hold of his penis without removing his clothes. There was no preamble. Rachel, mistress of ceremonies, eased her friend to the floor and the puppy needed no more encouragement. The little creature jumped with a sharp bark onto the woman’s rump and, with Rachel guiding his penis into the right position, he was in and humping her.

Aaron was fascinated. The sight of this kind of copulation was so new to him he forgot to stroke his penis at all. He sat with his cock semi-erect in his hand and gazed at the bucking of the little dog’s hips; saw Rachel ease herself under the pair to watch the penis slipping in and out of her friend’s vagina, reaching up once or twice to stroke her clitoris.

The dog scratched at the girl’s back and jerked his hips sharply. The moment of ejaculation, Aaron supposed. When he hopped off from on top of her there was a brief pause; it seemed the pair were fused together, and Aaron was reminded suddenly of the dogs he had laughed at in the schoolyard, locked together tail to tail after the act, surrounded by a bunch of giggling school kids.

Katherine and he would replay the scene in her bedroom, pretending to be the dogs. Crouching, rump to rump, falling over with their laughter. He remembered them discussing what this kind of behaviour was about. The male dog sticks its thing into the female. He remembered the hot and sweaty afternoon, not long after the framed picture of Romulus and Remus was hung on their wall, when Katherine first suggested that human men and women sometimes did exactly what those schoolyard dogs had been doing.

The man puts his thing into the woman’s thing.

Aaron did not remember ever having seen a woman’s thing. He must have seen Katherine’s because there were photos of them as toddlers sharing a bath, but despite their closeness they had been separated early in life, put in adjacent rooms, allocated different bath times even though they still used the same water. Aaron sometimes stroked his penis in the bath, and if he imagined that this was the same water that had been touching his sister’s naked body only minutes before, his little penis would get particularly stiff and a strange excited prickle would spread across his skin.

You have a boy thing and I have a girl thing. So maybe I am not your Remus at all.

Aaron thought about this. Their parents were out at the shops and they were sitting on the floor of Katherine’s bedroom, gazing up at the painting on the wall.

No, he decided. That didn’t make sense at all. You can’t see Remus’s bits in the painting, he pointed out. You can see Romulus’s thing but Remus might be made just like you after all.

Is your thing like that? She pointed up at the painting and Aaron felt a little rise in his groin at the thought of showing it to her.

Not really.

Well, what is it like?

Why? Do you want to look at it?

Her slow decisive nod. Aaron could remember it even now, her first gesture of consent. The excruciating humiliation of that first reveal, the aching twitch of his erect penis as she showed him hers.

It was more this memory than the image on the screen that had aroused him now. He took hold of his cock and stroked it, pulling the base of it down towards his body. Katherine sometimes still gave him a hand job, yet he always found his own fingers more certain, even after all these years. She had too light a touch, she tired too easily, losing the rhythm. Sometimes he wondered if his attempts, infrequent now, to pleasure her with his mouth had lost their power for her too. The times when she was on her knees before him he would have to concentrate to remember that he was not on his own.

The dog recovered in an instant. If only Aaron still possessed that kind of stamina. In the early days of living with his sister as if they were husband and wife, he was sometimes so overwhelmed by the idea that he could have sex with her whenever he liked that—lying in a pool of his own sweat, his face smeared with her juices, the condom still hugging his exhausted penis after their second coupling of the evening— he would catch just a glimpse of her spit-slicked breast and begin to harden for a third time. It seemed his lust for her would never come to an end.

He watched the dog sniffing around Rachel’s thighs; she had assumed the submissive position. The delicate fingers of her friend, Leda, were buried to the knuckles in Rachel’s glistening slit. Leda held her fingers out and the dog licked at them. He noticed the red worm of its penis slipping out of its sheath once more. The dog leaped onto Rachel’s back and she pushed towards him, shuffling her hips to meet his. She was as enthusiastic as the dog and it was sweet, too, to watch Leda ease back onto the floor, reaching up to massage Rachel’s clitoris, helping the girl to reach the orgasm that she seemed so desperate for.

Katherine used to be equally excited about their sex.

Sometimes they would fall asleep, his penis still held into the heat of her body, her arms locked around his shoulders as if she would never let him go, and then, in sleep, her body would still be hungry for him. The soft dance of her hips rocking back and forth and him, inside, once again becoming hard.

His orgasm was quick and inescapable. He came, and it was the image of Katherine, waking from sleep, surprised to be already in the midst of it but pleased nonetheless, kissing him deeply and pressing her breasts against his familiar chest. This is what tipped him over. This was always what tipped him over. The dog ejaculating into the enthusiastic Rachel was merely pleasant background noise.

The dog pulled himself free and his penis swung loose, dripping onto Leda’s face beneath them. A sight that many a man would pay for, he acknowledged, but his own moment of crisis was still reserved for the image of his sister-wife.

They agreed to meet again. They would, he supposed. This could be the beginning of a regular occurrence. They mentioned a barn, horses, and Rachel’s human mate who was not able to join them on this particular occasion. A pack, they called it, a family of lovers.

Aaron was not so much aroused by the bestial mating as intrigued by the strange mechanics of the thing. Yes, he would love to see them with the horses, mostly because he could not exactly imagine how that copulation would occur. And he quite liked Leda, the slight waist and dark thick hair that reminded him of the woman he loved. All roads led back to Katherine, it seemed.

Aaron closed the computer. He was suddenly exhausted. He dabbed at the dampness in his lap with a tissue. The apartment always seemed ominously empty at the end of one of these sessions, so that he occasionally wondered if he would bother again.

But they passed the time. Without the distraction of sex on a screen there would be just a large first-floor apartment looking out to another apartment block and another behind that. Lonely people, of course, stacked like Lego.

His life with Katherine was relatively insignificant when viewed, say, from the apartment across the road. Perhaps they would be shocked, those Lego people, to know that Katherine and Aaron Fitzgerald had shared a surname since they were born. Maybe there would be a raised eyebrow, nothing more.

Their sex life had begun in secret, the idea that they would be discovered was, perhaps, part of the initial spark. But they quickly moved from that first delicious revelation to other, more penetrative explorations.

Their parents, active in the church, were often out of the house performing good deeds, taking meals to the sick and the elderly, doing odd jobs at the church hall or organising plays with the youth group. They structured their dinner times as the pastor structured the morning services. The family would sit at the dinner table, stiff white napkins laid out across their laps. There would be thanks through prayer before the meal and a main course of cautionary tales, followed by the news of the day and family notices during dessert.

‘Your mother and I will be visiting Mrs Leonard tomorrow afternoon. Aaron, you will have to walk home after school with Katherine.’

‘No worries.’

They would eat their dinner with trembling fingers. An afternoon without their parents meant an afternoon of furtive exploration. They did not need to glance at each other to know that they had both begun, very slightly, to tremble. That night they would lie sleepless in their adjoining rooms. Aaron would scratch at the thin layer of plasterboard separating his bed from hers. Katherine would tap back. They had arranged their beds at exactly the same distance from the back wall. An aerial view of the house would look like a double bed with a partition bisecting it. They chose matching blankets, matching sheets. They even chose matching furniture and the same pale green paint for their walls, despite their parents’ suggestion that Katherine might like something warmer, a salmon colour or at least a peach.

Katherine had begun to shoot up to her full height and flesh out. She was racing ahead of her younger brother, who had only just begun to feel the first hormonal rush towards adulthood. Her body was a wonder to him and he often pressed his own pitiful flesh against the leaf-green wall, imagining that she would be pressing her ripening breasts against her side at that same moment.

On this particular occasion they walked home from school together in silence. They barely glanced at each other and yet, whenever their fingers touched, a jolt of excitement passed between them. Aaron’s little penis was rigid by the time they arrived back at the house.

Their parents were not there, of course, and Aaron could barely manage the key in the lock. He dropped it and was forced to bend and rummage in the mulched garden bed at the side of the front steps. Katherine, as always, was much calmer about it all. She took the key from his trembling fingers and fitted it easily into the lock.

‘I’ll get it, Romulus,’ she said. Aaron’s mouth was too dry to manage the reply—thank you, Remus—that he customarily gave.

Inside the house she was miraculously calm. She made them each a chocolate milk and Aaron gulped his too quickly, making sure to wipe his mouth, knowing that she would never kiss him with a childish chocolate moustache.

‘Good boy, Romulus,’ she told him then. ‘You drank all your milk and now Remus is going to give you your prize.’

She held his hand and led him to her bedroom. It always happened in her bedroom.

Aaron let Katherine lead the way. She had been the first into the world and had beaten him to every milestone since. Katherine was the one to steal the half-bottle of crème de menthe from the dusty sideboard, pulling back her heavy winter coat for him to see the neck of it nestled against her chest. She drank first, of course, and she was the first to tell him that he would not enjoy the flavour.

In the exploration of their bodies it was his place to wait for her invitation. He was often afraid that his excitement would become too much for both of them. Sometimes when she let him touch her body he imagined he would explode, and the shrapnel that hurtled outward from his disintegration would lodge in her skin, slowly poisoning her with his lust.

This was the afternoon that they had been waiting for. He knew it even though they had not discussed the possibilities of an afternoon unsupervised; she knew it too. Somehow her actions seemed weighted with purpose, the chocolate milk presented like a magic potion in a silver chalice, the few steps to her bedroom a ceremonial progress.

She unbuttoned his shirt first and he could see the thudding of his heart through the skin of his scrawny chest. Katherine began to take her school dress off, struggling with the zipper. He knew he should help her with it, but he felt as if his hands had swelled to the size of melons. He would only fumble roughly with the thin summer fabric. He was the Incredible Hulk from the comic book; in his clumsy exuberance he would somehow damage his delicate sister if he so much as attempted to unhook the clasp of her bra.

When Katherine had finished peeling their clothes off them they stood naked in the middle of the room. The she-wolf peered down maternally from her place on the wall as Katherine took Aaron’s head between gentle hands and guided his mouth onto her breast. He had seen these breasts appear, growing as if by magic, from two shapeless little pads to these perfect globes. His mouth watered every time he caught a glimpse of her erect nipples through the fabric of her uniform. It was difficult not to stare on those chilly mornings as they walked to school. Now, with his lips parting and the little nub of her excited nipple set firmly between them, he felt his own excitement bouncing up against his stomach. She noticed it too and slipped her hand down to curl around his penis.

How was it that Katherine knew exactly what to do? It was as if her body had all the rules of sex hard-wired into its flesh. She seemed to know just how to hold him in the palm of her hand, the perfect pressure on his penis, the soft comfort of her stroking fingers. Her body could excite and soothe, both at once. She dipped her head, craning towards her own breast, pressing her mouth against his, and found his tongue. He felt hers curl into his mouth, the two of them both tickling at her own nipple. The thought of this rang in him like a bell, an exquisite note that set his flesh to vibrate, and then it happened. The sudden rush of it. His knees buckling and his hips convulsing and he pulled back to gasp, and watch his penis throbbing in her hand.

There was spit on her palm. For a moment he was mortified. Had he urinated, just a little? What if he had disgraced himself and she was disgusted with him? But she looked up at him and no: nothing he did could disgust his sister. She was Remus to his Romulus. She reached behind them for a tissue and wiped the mess; held it up for them both to investigate.

‘You ejaculated,’ she said. ‘That means you love me very much.’ He nodded, unable to speak. ‘And you know what? I love you very much too. Feel how much I love you. Touch me and you will see.’

Katherine lowered herself to the carpet and spread her legs. He touched the dampness, dipped his fingers into the wet heat and brought them glistening to his face.

‘That’s my way of saying I love you. That’s my way of saying I want you to put your penis into me.’

‘You do?’ They both knew that this was going to happen. The afternoon was singularly charged, with a kind of adult lust that they had not experienced before. Their parents were away. They were alone with each other. It was inevitable that they would approach that final barrier to the world of adult games. Aaron was already hardening and with this new information he became even harder than he had before the ejaculation.

‘Yes.’ A grave nod. ‘Today is when we do it properly.’

‘But…it’s not wrong, is it?’ Aaron knew you shouldn’t do these things with your sister. The other boys made jokes about it, and then mimed vomiting, fingers aimed at their open mouths. He had met some of their sisters and he had felt proud to see that his own sister was smarter, wittier and more beautiful than any of theirs.

‘It isn’t wrong if you don’t ejaculate inside me. I will get us condoms next time, but for now I think it is safe if you just put yourself in and push just a little bit back and forth. If you feel like you are going to…’ she gestured vaguely at his groin, ‘do that again, you have to pull out. I know that will be hard but I will help you. Is that okay?’

And Aaron nodded. He was already climbing her body, hovering over her, holding himself up with his hands spread beside her shoulders. He jabbed with his hips and she shushed him gently.

‘Softly now. Slowly. Do you know what a virgin means?’

He didn’t, but he knew how to be gentle when she told him to. He lowered his hips till he was kneeling with his penis pressed against the little wet slit. She reached down and dipped her fingers into herself and spread the juices over the tip of his penis, holding the outer lips open and lifting her hips so that the end of his penis butted up against the tight warm wetness between her legs.

It was impossible. His penis would never fit in there. After several attempts, Aaron felt his cheeks blazing red and he rolled off her and onto his back. His eyes were damp and he rubbed at them crossly with his forearm.

Katherine rolled towards him, pressed her naked body against his flesh and whispered in his ear. ‘A virgin means I have a little flap of skin that must be broken before you can get your penis inside. It is going to hurt me a bit. Everyone says it is “exquisite” when you get over the pain and there’s a man’s penis inside you.’

A man. Aaron felt himself rising to her good opinion of him.

‘“Exquisite”. Isn’t that a lovely word? That’s what I want. I want you to be my first exquisite man, because I love you more than I love anything.’

She climbed on top of him then and eased herself into position. There was so much of her wetness now that he slipped away, across the slickness of her lips. Even this kind of rubbing on the outside was almost too much for him. He wanted to be inside her more than he could have imagined possible.

He saw her holding her breath and scrunching up her eyes and suddenly she was on him and slipping down around him, a gorgeous pained whimper and he was ashamed that inflicting pain on her also increased his excitement. He was a monster. He felt himself giving in to his own capacity for damage and just for a moment he wanted to cause her pain. He wanted to tear that little flap of skin she talked about. To hear her whimper again.

Aaron lifted his hips to meet her and grabbed roughly at her thighs. She made a little sharp noise in the back of her throat and it was done. He felt the tightness slip up over the length of his penis. He was inside her. Inside the body of his sister.

They stayed like that, a perfect fit, one inside the other like Babushka dolls. He knew in that moment that this was where he belonged. He wanted to stay here like this forever.

He had found his home and there would never be another moment as perfect.

She opened her eyes and stared down into his. Her pupils were large with her excitement. She began to rock there, lifting, settling down and the surge of lust was so overwhelming that it was only a matter of five thrusts before he felt the wave crashing over him. He lifted her hips off his and held her above him as his penis shuddered and began to pump out its second gush of seed. They both stared down at the place where the pearly drips arced up and into the new thatch of her darkening hair. When the shuddering was over she lay beside him and parted her thighs and they both looked in awed silence at his juices mingling with her own on the outside of her blood-reddened lips.

Aaron felt like he would never again see anything so completely holy; he had never felt this much devotion in prayer. He bent towards her torn skin and kissed the tender lips and Katherine smiled and wiped the mix of blood and sperm and her own juices from his face. When his lips were clean she kissed him deeply, a curl of tongue, an exchange of spit.

‘Now,’ she said, ‘no one can ever part us.’

‘Blood brothers,’ he said.

And she shook her head. ‘You can’t call me your brother anymore. I am a woman now. I am not your Remus, I am not even your sister now. You know, now I have become your wife.’

Aaron nodded, and the kiss he gave her was a vow; and when they were forced to pull away from the kiss so that they could breathe once more, their faces were wet with tears. Tears for the death of their brotherly pact. Tears for the birth of a new kind of love.

The bed was warm near Katherine’s body. He slid in between the sheets and inched over next to her. He still found her arousing. The smell of her skin, her hair. Such a familiar aroma, sometimes he mistook the smell of her sweat on a shirt for his own. This was the problem, he supposed. The curse of familiarity. Despite his desire for her it seemed, on the rare occasions when they did make love, that he was reliving a beautiful memory. He struggled to feel the immediacy of the act and, since his last birthday, he had begun to lose his ability to consummate at all.

Katherine assured him that this happens to every man as he trudges into middle age. She had turned forty herself a few years ago and Aaron realised that she was speaking about herself as much as him. At one time her orgasms would rack her body, arching her off the bed as if a giant hook had fallen from the sky. Her teeth would clench, her toes would curl and her hands would make fists around the sheets, tearing them out of the neat hospital corners Aaron had made.

The pulsing of her cunt was the most amazing sign of her shattering delight. He used to feel the clench, the tug of her muscles around his penis or his fingers or his tongue and it would be as if the palpitations might completely swallow that part of him. It put him in mind of astrological events, of a distant universe caught in the tractor beam of a black star, of planets wheeling around to their own death.

Perhaps it was only these last three years, perhaps it was already five or six; but he thought the force of her orgasms had been diminishing. The dark star almost spent. His own planetary trajectory remained constant in this less volatile environment. He had tested his theory with a finger the last time he felt her orgasm, the gentle palpitations. More like a sleepy infant sucking without intent.

Aaron had pressed his cold stomach onto her warm hip, draped one arm around her and let his fingers rest on the vaguely raised nub of her nipple. He looked up to where the Rubens print hung above them and wondered if now, after all these years, they had finally returned to their original roles suckling at the teat of life together: twinned once more in the manner of a brother and sister.

Aaron was asleep when Katherine returned from her run. He slept away the mornings. Sometimes she would open the door a fraction and wait, damp with sweat, her hair a tangled mess the way she knew he liked it. Aaron disliked the way she combed her hair back for work, clipping it coyly into a chignon at the nape of her neck. He liked her best as she was at this time of day with her cheeks flushed from running, pinched red by the cold morning air. Sometimes, in past years, he would wake suddenly and see her at what he said was her most radiant. She remembered him reaching for her, the gorgeous eyes heavy-lidded, still weighed down by sleep. And she would risk missing her bus to go to him, their need for each other suddenly reignited.

She waited, hoping, but he did not stir. Katherine sighed. She closed the door with a gentle click and crossed the corridor to the bathroom.

Her morning runs were the one true hour of joy in her life. After her shower she would eat a light breakfast, then drag herself to the library where she would spend the day shelving and shushing and listening to the pointless prattle of the other librarians.

It seemed that everyone else in the world found their neighbours endlessly fascinating. Apparently the distance of a swimming pool from a garden fence was newsworthy, so too a reality TV show about amateur cooks. There were so many of them these days that she could never really tell which show they were speaking about. Yesterday there had been a seemingly endless conversation about the colour of the bathroom cabinet in some television renovation. Would avocado really look good next to aubergine? They might as well have been speaking about a fruit bowl.

Katherine remembered, for a moment, the bedrooms of her and Aaron’s childhood. The light green paint; how they both fought to make sure their rooms were painted the same colour. She remembered the wall that separated their rooms, the sound of Aaron’s fingernails scratching at the barrier that separated them. The way she would press her breasts against the wall, just as she’d told him she would. The days when they had not yet touched.

She remembered this time with a little thrill of desire. The impossible idea of Aaron’s body pressed against her own. Some nights, she thought she would ignite with the heat of her desire. She would set the sheets on fire and the lime paint would crackle off the wall and if the wall charred between them and disintegrated their bodies would fuse together as if they had been born conjoined, twins that could never be separated.

Katherine dipped her head under the steamy heat of the shower. Aaron always asked her to use the fan, he worried about mould. But she liked the foggy damp that clouded the mirror, softening the lines and creases that had begun to appear. She was getting old. She could see it in her skin. No matter what creams or lotions she used, she could not banish the dry patches, the dark liver spots that had begun to spread on the backs of her hands. The cluster of moles that she had had on her neck since childhood now spread darker and more bulbous, and she wore heavy necklaces with her work clothes to hide behind.

No wonder Aaron spent his mornings asleep in bed, it spared him the clear light of reality. In the evening, when they crossed paths briefly before sleep claimed her, there were things to hide behind. Soft lighting, wine, the crocheted throw rug she pulled over her lap and up to her thickening waist. He sat beside her on the couch. They hugged, but he did not really look at her. They never fought; they still found things to laugh about, they agreed on movies, literature, art. And yet she felt, as she had before, a growing distance from her brother. Her lover, her husband.

The bathroom door opened so suddenly that Katherine fumbled the soap. It slipped off the rack and bounced off her toes to partially cover the plug hole. Water began to swish over her feet and rise to her ankles.

Katherine felt her heart beat faster. She looked out through the fogged shower curtain and saw the shadow of his naked body towering in the doorway. Aaron was so tall and impressive; more beautiful than any other man she had ever seen. Even after thirty years masquerading as husband and wife she could still catch a glimpse of him and find her breath stolen from her.

‘Hi darl,’ his sleepy voice. A radio voice, she always thought, deep and genuinely warm. ‘Just need to use the loo.’

She listened to the tinkling sound as he stood, leaning with one hand against the wall. She watched the sleepy sway of him, lust and tenderness rising inside her. In their first weeks in the apartment he would wake early like this, to find her in the shower.

She remembered one moment, years ago, with perfect clarity. The sliding back of the shower curtain—a dark blue at the time, with little raised bubbles in the plastic—and Aaron grinning, presenting his nakedness to her like a gift. Her reflex movement as she knelt under the play of water, unable to control her actions, pushing forward to take his penis in her mouth. Thirsty for him then, parched, as if the only thing that could restore her was the slippery jet of semen that he would eventually pump into her throat. She remembered how he tried to lift her to her feet, frightened, perhaps, that she would drown, wanting to kiss and touch her in return, and how she clung to him, pushing his hands away, pulling his hips closer, happy to feel breathless under the spray, desperate to feel him come into her mouth.

They had been sexual for many years, but the sudden removal of restrictions had opened up a world of play that they had never known before. They made love in the shower, on the couch, on the bathroom floor. He bent her over the kitchen bench when they were making dinner together, lifted her up among the chopped garlic on the counter top. One time he was inspired to put a Lebanese cucumber inside her and eat the whole thing, crunching the crisp flesh till his lips touched her slick wetness. Even then she felt him suck at the vegetable and devour it inch by gradual inch, salty and warm from inside her body, his shameless abandon making her juices flow all the more freely.

They experimented with every possible implement; she came to like the feel of a wooden spoon inside her, the crack of an egg on her pubic bone, the taste of honey on his penis. The bedroom they found especially erotic, playing at husbands and wives under the covers as they once had played doctors and nurses.

Aaron finished and shook off the drops, and she saw his outline through the curtain as he turned to face her. She wanted suddenly for him to come towards her, to pull back the shower curtain and reach for her. Her mouth was dry, the same thirst now as that very first week of freedom. She would swallow him if he would only take a few steps forward, she would grab at his hips and not let him go until she had drunk her fill. She watched as the shadow of him hovered just beyond her reach.

‘Do you need me to pick anything up this afternoon?’

The sudden flatness of her desire dissipating. ‘We need coffee.’

‘Okay. I’ll stop at The Boys.’

‘And anchovies?’

‘And the deli.’

She let the water cascade over her hair. She brought her hands up to her face and wiped the lather from her eyes. When she opened them again the shadow of her brother had disappeared, a creeping cold breeze tickling in from the door he had left ajar.

Katherine leaned against the tiles and closed her eyes tightly. She put her hand between her legs and pressed her fingers onto her clitoris. She imagined Aaron naked, still only vaguely awake, in their bed, his knees pulled up to touch the place where her body heat was still a memory on the sheets.

She slipped her fingers inside herself, remembering a time when he would have been here, eager to do this with his own hand. The way he would kneel under the spill of water, gazing up at her with his startling blue eyes. She imagined that instead of asking about coffee and anchovies he had stepped over to the shower and pressed the plastic sheet to her breasts. His mouth finding hers, the gorgeous suffocation of plastic forced between her teeth by the press of his tongue, his penis hard, tenting the curtain towards her, his hand reaching around and his fingers burying themselves inside her.

She imagined the curtain tearing off its rings, the fall of it encasing her, the sound of the shower drumming against the thick plastic. And he would lower her then just as she lowered herself onto the floor of the shower. He would leave her upper body blindly wrapped in plastic as he exposed her hips and eased her thighs apart. Her lips would be moist from soap and water when he prised them apart, but his tongue would find her own slippery juice and spread it along her labia, making sure her vagina was slick and ready for him.

Then the longed-for weight, the pressure of his body as he lowered himself onto the curtain. Again the plastic in her mouth, the barrier between their bodies only heightening the pleasure, his cock suddenly there, deep inside her.

Only in this kind of fantasy could she ever know him skin to skin. In dreams, his cock was the only thing that was naked, the one point where their flesh connected. In real life they were too cautious for him to linger inside her unprotected for more than a moment. She could never, in the real world, feel his semen shoot into her as she did now in imagination.

He was her brother. They treated his seed as if it were acid to her inflamed vagina. She could swallow it, she could smear it on her breasts, he could aim it onto the jut of her pubic bone; but it must not fall inside her.

Only here, alone under the heavy fall of warm water, she could spread her legs wide and imagine his violent final thrusts, the warm water a thin substitute for his hot semen, the feel of it splattering her moist labia, and when she spread the lips wide and thrust her own hips up towards the cascade of water, it was the idea of Aaron, her brother coming inside her that finally brought the spasms of release.

She felt the palpitations around her finger as Aaron must feel them, squeezing his sheathed penis when they made love. She luxuriated in the dwindling waves of pleasure; but when it was done, a terrible sadness rushed in to replace the sheer physical joy.

Breakfast alone at the kitchen bench. Coffee sipped from a thermos cup in the car. Katherine dragged herself towards another day with the other librarians, none of whom knew her particularly well, none of whom she liked. She strolled down the fiction aisles touching the books that were her favourites, Nabokov, Orwell, Eugenides, Nin. Books as friends.

Surely Anaïs Nin would have understood her situation. They might have huddled, heads close, in the tearoom. I am in love with my brother, I have always been in love with my brother, and Anaïs would touch her lightly in the small of her back and breathe into her ear so that the hairs raised up on her neck. If only I had had the courage to make love to my brothers. The three of us could have the two of you over to dinner. Our families could make out in the loungeroom over dessert.

‘You on first lunch break?’

Katherine started. It was the new boy, Trent, a slight young man with large brown eyes that stared up at her as if anxious to know whether she would pet him or kick him aside. She smiled. ‘I’m not that hungry. You can go first if you like.’

‘It’s a shame we can’t take breaks at the same time.’

‘Why?’ She didn’t mean her question to sound so terse. She saw him flinch: kicked, then. Already sidling away.

‘Oh, no reason, I just like this café around the corner and it would be nice to buy you a coffee. It wasn’t a thing, just a thought. But we don’t have breaks at the same time. So anyway. That’s—I just—I’ll take my lunch first then if you don’t mind.’

He was gone before Katherine could apologise. Leaving her standing forlornly cradling a copy of Little Birds.

Later, on her own lunch break, she pressed her forehead against the laminate of the desk as if she were praying to the apple she had placed there. She felt the dull throb of a headache beginning behind her temples. She lifted her face and checked her watch; groaned at the stretch of hours she would have to drag herself through before the day ended.

Trent was standing near her locker. Katherine was transported back to the school corridors for a moment, the young boys hovering, placing themselves in her way. They kept trying despite her reputation, calling her frigid because she always managed to wriggle politely out of the invitations to school dances or parties on Friday nights. They thought she was a career virgin, saving herself for god or country or a life of higher pursuits. They were not, of course, to know about her regular trysts with her brother, the quick consummations achieved furtively on her bedroom floor.

Now, as then, Katherine felt her cheeks redden at the sight of a boy waiting by her locker. She smiled at him shyly and he shrugged as if in answer to a silent question.

‘Sorry about before. I wasn’t trying to hit on you or anything…’

‘You weren’t?’

‘Well not, I mean, I could, I want, but I don’t know—I didn’t mean…’

‘It’s okay,’ she told him then. ‘If you still want to go for coffee I wouldn’t mind one now.’

‘Oh really?’

‘As long as you know I am married.’

‘Oh, okay.’

‘Over twenty years.’

‘What, really?’

‘How old do you think I am, Trent?’

It was his turn to blush. ‘I hadn’t really thought about it.

I suppose you are a bit older than me.’

‘Yes. A fair bit older, I would imagine.’

He shrugged again and pulled his satchel higher on his shoulder, a sweet little self-conscious gesture, and Katherine found herself smiling.

‘Actually that café closes early,’ he said, ‘but there’s a cute little bar next door.’

‘Come on then.’ She threaded her hand into the crook of his arm, and found it was nice to walk like this beside him. He seemed like a sweet enough person. Katherine had not gone to a bar with anyone for so many years.

She took Trent around the corner from the bar and kissed him on the mouth. His route home was in one direction, she would be going in another. Before the point where their paths diverged there was a small alley between a Chinese takeaway and a little bookshop. Perhaps it was the window display: some rejacketed classics and Little Birds now with a shy girl on the cover, naked, her smile that perfect mixture of brazen and coy. It was Anaïs, egging her on.

Katherine took the boy by his collar and before either of them could protest she eased him back into the darkness of the alley and leaned him against the warm bricks and pressed her lips hard against his mouth.

It was the first time she had kissed another man. All her life she had reserved her kisses for her brother, from the first platonic ones to the kinds of kisses that would inflame them both. The feeling of another man’s mouth against hers was strange and arousing. His face was so smooth she could rub her cheek against his without the slightest risk of a beard rash. She threaded her fingers through his hair and kissed him again, longer this time, parting his lips with her tongue.

She knew it was the novelty that excited her. The idea that this tongue belonged to someone completely unrelated to her. The smell of his skin, so different. Tart, with a hint of citrus, the feel of his skinny chest pressed against hers.

Katherine was suddenly filled with a sense of urgency. She held his hips against her and there was his erection. Another man, not Aaron, finding her attractive in this way. There was no love, no memories of childhood tumbles, no fights over the washing-up. The sex with Aaron had been exciting, always, but it was infused with all the complications of a deep and unassailable love. This man was simple. He was no one to her; she could walk away from him tomorrow and her life would not be diminished. And it was with complete understanding of how unimportant it was that she took his hand and moved it under her skirt.

She was wearing thick winter tights and his fingers scrabbled at the waistband. He was not gentle and sure, like Aaron. His nails scratched. When his hand finally found a way into her knickers, the fingers were colder and thinner than her brother’s. He slipped one finger inside her but it was not enough. Even with his whole hand, the fingers bunched into a kind of pointer and pushing into her, even then she did not feel as full as she did with Aaron’s fingers.

Still, he was keen and very nervous. His shaking hand filled her with tenderness and she hugged him closer. She wanted to take him into her body to calm him. She reached into the low-cut shirt she was wearing and pulled one of her full breasts out, and Trent dipped his head to lick at the nipple pointing up at him.

She felt the bounce of his cock pressed against her leg inside his trousers. If they were both naked perhaps he would have slipped it into her now; she was certainly wet enough. There would be nothing to stop him from laying her down in the dirt, pulling down her tights and her knickers and slipping his cock inside.

Once the thought was out, she seemed unable to drag it back in. She pulled him down onto the pavement with her, the red light from the Asian restaurant spilling onto her feet. She glanced at her sensible heels and, with deliberation, kicked each shoe off. Trent was kneeling next to her, his mouth still suckling at one of her breasts, his cock still straining at the tent of his pants. She wanted him to take her tights down. She needed his flesh inside hers but he seemed content to suck at her breast.

She reached out and touched his penis through his trousers. It was harder than Aaron’s cock had been for a long time. She felt the tip of it leaking dampness through the fabric, the sign that he was excited. When they were still young, Aaron would drip the juices of desire all over her stomach. She loved the feel of pre-come and the taste of it. She slid her fingers up towards his zipper and the gasp he made as she eased it down was flattering. She slipped her hand inside and there was only the thin cotton of his underwear between her hand and his penis.

She lay back, her hair in the dust of the alley, her breast slipping away from his lips. A position of submission. He could climb onto her now, with his cock this hard. It would be so easy to take it out of his pants and spread her legs wide enough and slip it inside her. Instead he seemed frozen. Kneeling, his head bent as if in prayer, his cock hard under her hand.

She reached under the elastic of his underwear and there it was, the softest skin on his body, the slippery wet head coating her palm with juice as she moved her fingers along the shaft. She could smell the excited musky odour, a masculine scent, a scent that made her shift her hips unknowingly, to lift her knees and raise her groin towards him. She felt as if all her blood had pooled between her thighs, her lips swollen to the size of a split melon. She knew he would be able to smell her too. There was that damp earthy female smell that she emitted when she was aroused. He leaned over her until his lips brushed her chest.

‘I’m not sure you should do that,’ he said, and it was a throaty voice, sandpapered with desire.

‘Do what?’ She slipped her palm over the head of his cock. She spread her thighs wide. The crotch of her tights was soaking by now, she would have to hide them at the bottom of the washing basket when she got home, and here in this moment it didn’t matter to her at all. He sucked her nipple into his mouth and she felt it draw a tight line down into her clitoris. She was on the edge. All he needed to do was to straddle her, shift his weight. She didn’t even need him to undress. She would come as soon as she felt the head of his cock plunge into her wet flesh. She reached down with her free hand to lift her tights down away from her crotch, the cold air brushed over her skin. It would be too late if he waited any longer, she would be gone.

‘Oh god.’ He bit down on her breast and sucked in suddenly. She felt his cock begin to pulse in her hand and pressed her fingers onto her clitoris. The orgasm swept over her with such violence that her hips thumped against the pavement. She would be bruised and sore but in that moment of release she did not care. She clenched her jaw and heard the grunt that must have escaped from her throat, the sound of an animal snuffling at the earth. She thought of truffles, tasted the rich dark flavour. He eased away but it wasn’t over for her yet. She felt her back arch for a second time and her hand, slipping out of his trousers, clasped at her mouth, the taste of his come on her fingers, smeared onto her chin and her cheeks, the smell of him and the dance of her body and for a while she felt like it might not stop. She rode another wave of contractions, her throat exposed to the night air and his gaze.

‘Oh man,’ he murmured, ‘you look awesome.’ He held her shoulder gently as she finally felt her chest release. Katherine relaxed onto the footpath, gasping for breath.

‘I wish you could have seen yourself,’ he said, wiping the glistening juice from her lips, ‘you look so sexy when you come. I can’t believe I just saw that. It was amazing.’

Katherine took a series of long and shaking breaths. Her breast was slicked with spit, the nipple pointing out from her clothing. She pulled her bra and dress back over it. His semen was drying on her mouth, her hand crackled with the feel of it. She watched him wipe his own hand on his shirt, her juices, her scent marking him.

He zipped up his pants and brought his fingers towards his nose, a sweet unconscious gesture as he smelled her sex on his hand. It was almost enough to rekindle her desire. She was aware that she had not seen his penis, not taken it in her mouth or, better, her body. She felt suddenly ashamed for thinking this way and pushed herself up to a sitting position, stroking her hair back away from her face, lifting her tights back to hide her wet and flushed sex.

‘I’m…’ she was about to say ‘married’ but realised that she had said this several times already. Realised also that she had been the one to drag him into the alley beside the bookstore, it had been her lips that kissed him first, her hand that found its way to his penis.

‘I’m sorry,’ he interrupted.

She kissed his cheek, laughed a little nervously. ‘Don’t be. I was the one who…I don’t know what got into me.’

He stood and helped her up as she brushed at her skirt. She turned for him to wipe the dust from her back, feeling like a teenager. Laughing a little nervously when he picked a lolly wrapper out of her hair.

‘It won’t be weird at work tomorrow?’

‘I suppose it might be. Maybe we should agree to go for another drink. Just to normalise it. We will probably laugh about this in the future.’

He laughed now but it sounded strained. His penis was already beginning to stiffen once more, a clear hard outline inside his pants. She felt the urge to let her fingers circle it again, a fond farewell hug.

She closed her eyes and stepped away from him. ‘Time for me to get home.’

‘But I’ll see you tomorrow at work?’

‘Yes.’

‘Then a drink after?’

‘Yes. I think so, I’ll just have to check with Aaron. I don’t think we have anything planned.’

‘Okay.’

They hugged goodbye a little awkwardly. Katherine turned and walked towards home, a quick, shallow heartbeat pacing her. She wondered if Aaron would notice her anxiousness. What would she say? She was already very late.

She paused outside their apartment block and smoothed down her clothing. She thought her hair might be a little dishevelled; she unclipped it and let it hang free.

Dinner was ready. She could smell it, a roast. That was a surprise, Aaron usually did something light in the evenings. She wondered for a moment if she had forgotten some special event, a birthday, the anniversary of the day they first made love. Aaron was sitting at the kitchen bench, his laptop open. Katherine saw a flash of video on the screen, too far away to make out what he had been watching. When he heard the front door shut behind her he folded the computer closed quickly and hurried across the room to kiss her hello.

She smiled as casually as she was able. She had washed her face and gargled at a water fountain but still she wondered whether he would be able to smell another man’s semen on her breath. But the kiss was quick—brotherly—and she hugged him with real warmth. He seemed not to notice the creases on her skirt, the tiny smear of dirt on her dress, next to her left breast.

‘Sorry I’m so late. Drinks after work. They want to make it a regular thing, too, which I’m not sure is such a good idea. You know the people I work with. I suppose I should go to the first couple before I start making excuses.’ She was talking too much. He would think something was wrong if she didn’t shut up. She moved past him into the kitchen. ‘Something smells amazing.’

That night she reached for him in her sleep. She rubbed herself against his soft flesh, opened her eyes and discovered that it was his pillow pressed between her legs. It was very late. She checked the clock and after a moment the green glow of the clock face organised itself into recognisable numbers. Two o’clock. She rubbed at her eyes, swung her legs out over the side of the bed.

Aaron was in the kitchen where she had left him, with the laptop open on the bench. He had his earbuds in and was nodding, typing one-handed. Odd. He always touch-typed with both hands. She took a step forward. She would have said his name, but he wouldn’t hear her with the earphones in.

When she was close enough she noticed that there was a picture moving on the screen. She crept forward, her feet silent on the carpet. She thought it might be someone naked. Yes, a girl. He was watching a naked girl. The girl was facing the screen, her body gyrating, her breasts dangling beneath her. Something was wrong with the picture.

Katherine took another step forward, squinted into the dark. The camera was being moved. The girl was side-on to it now, propped up on her hands and knees. Her face showed pain. Or, no, maybe pleasure. Katherine was no stranger to that fine line herself.

The girl was crouched beneath an animal. Some kind of small horse, a miniature pony, and as she watched she realised the rocking motion was being driven by the animal’s thrusting. She watched as the creature drove its hips against the girl. She was watching sex. A girl having sex with a horse.

She was appalled and suddenly horribly aroused. Aaron typed something into the computer with his free hand. She was too far away to see the tiny letters that appeared at the side of the screen. Was he talking to the girl? Was he talking to whoever was holding the camera?

There was another person in the room, someone who was showing her brother these disturbing images, and Aaron was…Katherine realised, with the same mix of disgust and desire, that her brother was moving his hand in his lap. Stroking in time with the horse’s thrusts. Aaron was masturbating one-handed while he carried on a conversation about the scene with the other.

She stepped backwards. One careful step at a time. On the screen the animal lunged, then stepped back. She saw the huge engorged penis slipping out of the woman’s sex, saw the sperm cascading out of her, saw her brother pick up the pace, racing towards his own pleasure. She turned and fled upstairs, diving into bed and pulling the sheet tightly around her own body.

Aaron was downstairs watching porn. Aaron was watching bestial porn. Aaron was masturbating to weird, hardcore, bestial pornography.

The image of the penis emerging from inside the girl, the gush of semen, so much semen. She closed her eyes but it was still there, the picture of it, clearer in memory than it had been on the screen. The final thrust, the pained, ecstatic expression of the woman, the undulation, her tits rocking back and forth, the sudden back-stepping of the horse, the penis—such a huge penis for so small a creature—and all that ejaculate.

The image of it repeated. She did not want to admit that it aroused her, every repetition making her feel more alive to the sensations of her own skin. This shock so soon after her first kiss with a man who was not…A stranger’s fingers inside her own vagina. The idea of the horse somehow tangled with the feel of his whole hand slipping up and under her knickers, the thrusts from the knot of his fingers blurring with the thrusts of the horse. The quickening rhythm of her brother’s hand on his cock, the way he used to let her watch him masturbating above her in their bed, the spray of his come splattering her breasts, her chin, the feel of it dripping into the thicket of her pubic hair, the gushing come of the horse slipping out with the fat dark shaft of its penis. She was coming.

She tried not to, kept her hands clear of her own flesh, but the images became a barrage, overtaking her consciousness, spilling their poisonous seed onto her cunt.

She convulsed. It was overwhelming, the palpitations racked her whole body. She clamped her thighs together, hoping to step back from the edge of her excitement, but it was too late. She plummeted and her body took her on a ride more powerful than the orgasm of that evening in the alleyway.

The climax left her panting, sweating and confused. She heard footsteps on the stairs and turned quickly onto her side, pressing the palm of her hand against her chest where her heart still thudded so powerfully that surely the whole bed would rock with the force of it.

Her brother undressed and slipped into bed. She held her breath as he settled onto the pillow. She could smell the faint odour of his excitement and she wondered for a moment if he could smell her too. The two of them, as always, bonded in their mutual desire and shame. She lay with her eyes tightly shut, her hand pressed against her still-thudding chest.

She felt his hand rest lightly on her hip, felt herself stiffen slightly. She wanted him to know that she was asleep, deep in sleep, so deep that even his gentle caress on her thigh would not wake her.

Eventually Aaron took his hand from her thigh, turned over onto his side and seemed to settle.

She realised she was gulping her wine and set it down on the bar in front of them. Trent was smiling at her. He had noticed too. She blushed and laughed.

‘Hard day at the coalface?’

She nodded. ‘You?’

‘Oh, you know, the usual. Rescuing kittens from trees, healing the sick, saving the world.’

‘Didn’t know a librarian’s lot could be so exciting.’

‘Oh yes. I only got into this job for the thrills.’

‘I only got into the job to avoid the library fines.’

He laughed. ‘I suppose we are both in it for the books.’

She lifted her glass and tapped it against his. It set up a pretty bell-like sound that rang as she lifted the glass to her lips. ‘So how is the Galgut, anyway?’

‘Have you been stalking me?’

Katherine grinned. ‘I saw you put it in your bag. I wanted to read that. I loved his other books.’

‘I don’t know if I like it yet. It is good, but not like the last one.’

‘Which I loved.’

‘No, which I loved.’

They grinned together and then fell into an awkward silence. This was the moment when they should talk about what happened yesterday in the alleyway. The ghost of the act hung in the space between them and Katherine had to sidestep it to see Trent’s face at all.

‘Well,’ said Katherine, upending the last of the wine between her lips, ‘I suppose I should go home.’

‘Yeah. I should go too.’ They stood. There was an awkward moment at the door, where Trent rested his fingers in the small of her back just as she turned. Then his hand was on her stomach, too low to be anything but sexual. He snatched it away as if it might burn her skin.

‘I was going to say something completely inappropriate,’ she told him then.

‘Were you?’ he said. ‘Say it anyway.’

‘I was going to ask if you would walk me to the alley by the bookshop.’

‘And you changed your mind?’

‘No.’

‘Then ask me.’

‘Will you?’

And Trent said, ‘Yes.’

It was difficult but somehow they managed it. She was tall enough so that if she lifted her leg and leaned forward she could touch his penis with the slippery lips of her vagina. After that it all happened very quickly. She turned him, eased him backwards. And her fingers were fumbling with his fly almost before she had found his tongue with her own. She wouldn’t put him inside her. She only meant to touch herself against him, rub the hard tender skin against her clitoris. Only this kind of connection would temper the heat at her groin.

She didn’t mean to fuck him, not really, but once their genitals were touching she was overwhelmed by the idea that this was not her brother. His seed was not at all genetically similar to her egg and somehow even the idea of this otherness was enough to make her lose herself in her desire to have his cock inside her, dripping as it was with pre-come and then when it was in her she began to raise and drop her hips, milking him, desperate for the one thing she had never felt before.

‘Come in me,’ she said in his ear and the years of properness melted with this one lewd idea. ‘Shoot come in me, I need to feel it.’ And in her head the horse mounted the girl, the big cock pulling back and away, dripping its semen onto the ground. ‘Come on,’ she whispered in his ear, the urgent heat of her breath infecting him, making his hips jerk up to meet hers at a more urgent pace, ‘I can’t hold off, I’m going to come. Do it now.’

And he did. She felt it shooting into her and pushed her clitoris hard against his pubic bone. Her palpitations gripped him so tightly that he gasped and she heard him whimper oh god as if this moment of orgasm might be his last, a sudden wilting of his spine and she felt the juices spill out, dripping down towards her knees. And yet she was loath to release him from her embrace.

‘I’d fuck you again now if I could,’ she said into his neck, her voice hoarse. She barely recognised herself now. ‘I’d lay you down and ride you till you begged me to stop.’

And his whisper, shuddering into her ear, ‘Do anything you want to me. You want me on the ground?’

She nodded and he slid down the wall until he was sitting, braced against the brickwork. His cock slipped out from inside her. The horse backing out of the girl. She slipped with him, onto him, crouched over him.

She had planned this. In the morning, choosing her clothes for the day, she had picked a long skirt. She could wear this without her usual thick tights. She’d picked her highest heels, just a small rise, but pretty shoes, dancing shoes, fucking shoes. She almost picked out the black lacy underwear that Aaron used to like so much, changing her mind at the last moment, choosing instead to go without underwear at all.

All day at work she had been aware of the spreading dampness trickling down her thighs; she had hummed with a sense of potential. When she saw Trent in the children’s section, him with a copy of Black Beauty, her with Brown Skin Blue, the chance meeting seemed infused with potential. She imagined them entwined on the giant Hungry Caterpillar beanbag, tangling beside Shaun Tan and Narelle Oliver. Their hands brushed as they sidled past each other in the aisle and she felt the brief contact deep in her cunt, a twitching of the muscles there. Her nipples snapped into tight balls.

She settled into his lap now, and his cock was already slightly firm again. She could feel it with the lips of her vagina as she rocked forward and back against it. He raised his head to her singlet top. The nipple was still peeping above the neckline, still damp with his spit. He bit at it gently and then sucked it into his mouth. She felt his cock swell as he did it. She tested it with the sperm-slick flesh of her cunt, and it was firm enough. She raised herself a little and reached down to position him directly beneath her. When she settled onto her knees his cock slipped inside her. He suckled and she felt the thickness grow, pushing further.

She slipped her tongue into his ear and he pushed his hips and she felt him thick and slippery in her most sensitive parts.

‘You came in me,’ she said, as if this was new information that she had only just realised. ‘I have your come inside me. I want you to do it again.’

He lifted her easily, holding her head as a father might hold a baby when he laid her down on the pavement; a gentle cradling. In the next second his thrust was so forceful that she felt her hair pulled sharply by friction against the concrete.

She lifted her hips and pushed back, filled with a violent kind of need. She wanted him bruised from his contact with her hips. She bumped up against him so hard that his hand slipped and his chest thumped onto hers. She heard the sound of his pleasure or pain, felt his fingers slip down to grab at the flesh on her hips. He held her still and pushed into her again, a series of hard thrusts.

She spread her knees as wide as she was able. She wanted to feel his come shoot right up into her guts. She wanted to feel his cock pulse at the door of her womb. The damage was done now and she was determined to underline it with this second, deeper connection. He pulled back and she groaned sharply in disappointment. She tried to lift her hips up higher, but he held them firmly against the ground.

‘Hang on,’ he told her, ‘I don’t want to come too quickly.’

‘Come like a horse,’ she said, shocked by the coarseness of her language. ‘Come like you are going to tear me up inside.’

‘Oh fuck.’

And he lost his grip on her just long enough for her to struggle out from under him, tipping him onto his back like a wrestler taking advantage of a particular hold, flipping him and climbing him with a frantic desperation. She bore down on his cock, plunging her body up and down, taking as much of him into her at each thrust as she could hold. She reached her climax on the thud of a downward motion and he kicked back up into her, gripping her waist so tightly that his fingerprints would mark her for weeks.

He came. She felt it, the hot gush of his seed pumping into her. His open shirt was in her fists, his hips were bucking and she gripped him with her cunt, drinking him to the last drop, fresh sperm adding to the orgasm before this. She was swimming in his slippery juices. Her hair was tangled and sweat-slicked, her skin so damp that she seemed to glow in the spill of fluorescence from the Chinese takeaway. Her nipples glared out over the singlet, over the bra that had been so roughly pulled down. She was glorious in this moment and he spasmed one last time, his eyes wide with wonder as he burned the vision of her into memory.

She took a shaky breath in and stood. His cock slipped out of her with a sucking sound. Her cunt dripped and the splashes dotted his stomach. She felt in this moment a power she had never known. She had fucked him twice without love. She had fucked him and he had let her take his sperm into her.

She stood above him, sweating, panting, shaking back her tangled hair. Her flesh spilled from her top, her skirt lay like an abandoned skin on the footpath beside them. The red fluorescent light outlined her still-hard nipples and turned her matted pubic hair to flame.

There was the rhythmic click of someone walking past across the street. They might be seen. Someone might turn into their alley and find her there in this moment of glory. For once, the thought of discovery did not cause her anxiety. She would stare them down, dare them to comment. She had just had sex twice with a man she barely knew. The kind of sex other people enjoyed, sex with a man who was not a relative. Sex with a man to whom she owed nothing.

‘That was amazing,’ he said quietly. ‘I have never had sex with a married woman before.’

‘Well. Now you have.’

He reached for her hand and she helped him up from the dirty footpath. She could see the damp stains on the pale fabric of his open shirt, wondered if her own shirt would show the signs of their coupling. Would Aaron know? Would he be able to tell?

‘My husband watches pornography on the internet while I am asleep,’ she said. She had thought she might be ashamed to make this confession; it surprised her to find she wasn’t.

‘Is that why you just had sex with me?’

‘I suppose it is. Is that terribly wrong?’

‘Maybe.’ He shrugged. ‘I’m glad you did. You are by far the most gorgeous woman I have ever fucked.’

‘Seriously?’

‘Have you looked in the mirror, ever?’

Katherine found herself blushing again, the succubus banished. In her place, this shy angel lowered her eyelids. She noticed her breasts still spilling out of her singlet top and adjusted herself. Looked around for her skirt; bent and held it pressed to her naked loins.

‘Katherine, I am sorry if you are going through something difficult at home, but I am also not sorry because what just happened was incredible. I just hope you don’t regret it too much. And if it never happens again, well—that one time was so awesome.’

She kissed his cheek and she paused, choosing her words carefully. ‘You are the only other man I have had sex with apart from my husband. Ever. In my whole life.’

‘Really?’

She nodded.

‘Well, any time you want a repeat performance. Any time. Seriously. All you have to do is mention this alley and I’ll be hard in a second.’

She laughed. ‘I like you, Trent. But I don’t know you very well, and also I love my husband very much.’

He glanced at her and she watched his shoulders begin to shake as he was overwhelmed by a fit of giggles. It was infectious. She laughed with him.

‘Oh god,’ she said, ‘we are ridiculous.’

‘It’s okay if your husband watches porn on the internet, you know,’ he told her when he had his breath back. ‘Everyone watches porn on the internet. It’s no big thing.’

‘It isn’t?’

‘Nah. Everyone I know does it. I do it.’

‘What do you watch?’

‘I don’t know. Girls doing it together, hetero stuff, some gay boy stuff sometimes. Not that I’m gay or anything, just that it’s interesting, you know? I don’t think what you watch is any reflection on who you are. It’s like how you like Lolita— come on, I saw you reading on your lunch break. But it’s not like you are a paedophile.’

‘Don’t you think Nabokov is different?’

‘Sure. It is incredibly clever writing,’ he shrugged again, ‘but what’s the difference really? It was considered to be pornography when it was first published.’

‘So you are trying to tell me that one day my husband’s internet sex will be seen as great art?’

‘Course not. I’m just saying watching it doesn’t make him a bad person.’

Trent began to button his shirt. His penis hung out of his tugged-down pants like a wilting flower. He slipped it in and zipped himself up, trembling and laughing. ‘Look at my hands.’ He held them out and let her watch them shake. ‘You know my knees are like jelly now?’

She took his hand and stood brushing the dust from the back of her dress. ‘I know I shouldn’t have made you come inside me. I’ve just…it never…’

‘Well I’ve had my tests, but you shouldn’t take my word on that. You’re on the pill, I take it?’

‘I’ll get the day-after pill tomorrow.’

‘Okay. Thanks. And, just, thanks.’

She grinned. ‘Crazy. Anyway. I had better get home.’

He kissed her a little awkwardly and they walked off in their separate directions. Katherine glanced behind her at his retreating form. He looked so slight and vulnerable. He looked so unlike Aaron. Sweet boy. Someone she could like but could never grow to love. Still, the passion that had overtaken her so suddenly made her smile a little. She could barely believe what had just happened.

Katherine stood at the entry to her apartment block. She held her card up to the electronic lock. Touched the doorframe to get her balance. Aaron would be waiting for her. Aaron would be inside. She took a deep breath and pressed the button to call the lift.

Two in the morning. Wide awake. She felt alive, her body tingling with wakefulness. She realised now that she had been asleep for many years. Finally she had woken, and the world had changed in her absence.

She placed her feet firmly on the carpet, moved quietly down the stairs. Aaron sat in front of his computer. This time he was settled in the lounge chair, facing away from her, the back of the chair obscuring most of the laptop, which was perched on his knees. Again the rhythmic jerking of his elbow. She could see it rubbing at the arm of the couch.

She stepped forward as quietly as she could, peered around the high back of the lounge and saw a man on the screen, his penis in his fist, a fast and furious tugging.

She placed her hand on the couch gently, so that Aaron did not feel the touch of her fingers, and watched him watching some other man.

It was as if she were observing him from a great distance. She watched his hand on his penis, the quickening of his rhythm. She knew him so well it was almost as if she were standing outside herself, watching her own body bring itself to climax; he was close.

She bent towards him. At the moment of ejaculation she lowered her face to his ear and slipped her tongue inside it; he had always liked that.

This time it made him leap from the chair just as his ejaculate leapt from his penis, and sent the computer crashing to the floor.

They sat at the kitchen table. Aaron poured a shot of vodka for each of them.

‘Ready?’

It was ridiculous. She laughed. She tipped her head back and swallowed the liquid, feeling the slow burn of it coursing down her throat.

‘What are we?’ she asked him. ‘Eighteen?’

‘Do you remember when you were eighteen?’

‘God, you were so skinny. Do you remember?’

‘And you, Kiss-Me-Kate, always thought you were right. My year of being right. Remember?’

‘How awful.’

‘Wasted on the young.’

‘Yes.’

He filled her glass once more, tipped more vodka into his own glass. ‘I loved you so badly I thought I was going to die.’

‘I still love you, you know.’

And he kissed her then, gently, and when he pulled away from the kiss said, ‘So do I.’

‘So. How does this work.’

‘You sure?’

Katherine wondered for a moment. Placed her hand on her stomach. There was an excited whirlpool starting deep in her guts. Half elation and half fear. That perfect mix of emotions. She gazed into his deep blue eyes and nodded carefully. ‘Never surer.’

‘All right,’ he said. ‘Hold on tight. Get ready for the ride.’

Katherine was gorgeous. A simple fact: his sister was extremely beautiful. She had been since high school, when her body caught up to her sudden height. She’d grown into herself quickly, developing a kind of grace that set her apart from the other girls. He would watch her from a distance, noticing the attention of the boys. Katherine would meet him at the school gate and they would walk home together, tight as they had always been, and the other boys were jealous as he took her satchel from her and carried it all the way home.

His sister had only become more beautiful with age. He opened the world wide window and felt himself glow with pride. Katherine was still here beside him, still the most beautiful girl he had ever seen. Aaron understood why she had strayed, albeit briefly, and was grateful that she had made her decision to stay by his side.

‘You call them up directly? Like a telephone?’

‘Oh no. It is a completely random connection. Unless you have exchanged your Skype address with them.’

‘You do that? Exchange addresses?’

‘Only twice. The first girl was called Susanna. I never saw her face but I suppose that is the closest I have come to infidelity.’

She lowered her eyes, he saw her cheeks begin to colour at the mention of the word.

‘Maybe you should have met up with her in person. It would serve me right, I suppose.’

‘God, she might have been a boy for all I know. It is like that on the internet.’

‘And the second exchange of addresses? Did you fall in love with her too?’

‘Ah no. That was the zoo girls. I suppose that was more curiosity than anything. The world is a strange and various place. That is one thing I have learned in all these years.’

He typed an address in the bar at the top of the screen and an image flicked up, a man’s torso. She could not see his head. His body was a different matter, or one part of it was: there was a huge red cock in his fist, bigger than anything Katherine had ever seen on a man. She held her hand in front of her mouth to hide her sudden laughter.

‘Can he see us?’

‘Not yet. I can turn our webcam on if you like.’

‘Can he hear us?’

‘Not until I activate the mic. Do you want him to hear us?’

She touched his arm. He could feel the excited energy radiating off her.

‘I think we should get our story straight first.’

‘What story?’ He liked the sweaty glow of her skin. The widened eyes. The way she perched forward on the chair.

‘They don’t know who we really are or where we live, right?’

He nodded.

‘So we could tell them any story we wanted, right?’

‘Yes.’

‘So why don’t we tell them the truth?’

‘The truth?’

‘They’re going to think we are lying anyway,’ she said with a little half smile. ‘They’ll think the sister-brother thing is just a tease. The fun will be pretending to lie by telling the truth.’

Katherine took charge of the game. She had always taken charge. When they were kids she would organise their days with military precision. Now she ordered him to turn the webcam on, told him he should take his clothes off. Started to undo her own buttons as if these were the rules of the game they were about to play.

‘Are you sure? The internet can be a dangerous place.’

She pulled the computer to face her, unclipped her bra and angled the camera to take in the sight of her generous breasts.

‘Well hello there,’ said the man on the screen in front of her. ‘Aren’t you a sight for sore eyes.’

‘Sore cock too if you keep pulling it like that.’

His gorgeous sister. He remembered now how sassy she had been when they were kids, the filthy language flowing so prettily from her mouth. Somehow in the intervening years he had forgotten this, recasting her as an angel, something sweet and untouchable. He wondered now how long this had been happening. The illusion of her politeness was certainly shattered as she settled into this conversation.

‘Who’s that man there?’

‘Him? He’s my lover.’

‘So am I going to get to watch you be lovers?’

‘I suppose you will. But there’s something else about him you must understand.’

‘Oh yeah?’

‘He is also my brother.’

‘Really?’

‘Yes, really. We used to play doctors and nurses under the kitchen table when we were little.’

‘Yeah?’

‘You think I’m making it up but in fact it is true. Shall we show them, Aaron?’

‘Darling, I will do whatever you tell me to do.’

And he would. He was waiting for her instruction, she was in charge. He lifted his arm as he was told to and pulled his shirt over his head. He showed the man his penis when she ordered him to.

‘Call me sister.’ And he did, the word so strange on his tongue after all these years, and yes, it was arousing to remember that this was a most unusual connection.

‘My sister,’ he whispered into the small of her back, and followed her lead as she leaned herself across the back of the chair.

‘Spread me for him. Show him how wet and damp my sisterly love can be.’

And he opened her to the camera and marvelled along with the naked stranger at the glistening excitement of his sister. He slipped himself inside her and it seemed suddenly to be a breaking of taboos, this coupling that had become so ordinary in their day-to-day lives became a kind of transgression through the lust-filled gaze of the stranger.

‘He can’t come inside me, you know. Because it is sibling sperm. He must not come inside me. See him holding back?’

And suddenly Aaron needed more than anything to come. He tried to think of other things. Ham sandwiches on white bread and, when this did not work, their mother making ham sandwiches on white bread. But even this idea only added an extra layer of arousal; he remembered suddenly the wonderful excitement of the fear of being caught.

That time when their father popped home to pick up a letter he had forgotten on the kitchen bench. The terrified cessation of all movement. Aaron pausing mid-thrust, his sister lying face-up with her hips raised up on a pillow, the glorious sight of her new breasts so young and firm, her eyes wide with the knowledge that this might be about to end for them. The moment stretching out; their father calling out his name.

He remembered his voice shaking as he yelled back that he was in the bathroom.

Okay, well, we’ll be home pretty late. Make sure you feed your sister. And then, hearts pounding as the car pulled out of the driveway, his sister’s relieved laugh. Go on, then. Feed your sister. And his excited answer with each thrust of his hips. Feed her? Like this? Eating it? Eat it. And the wonder of her slipping out from under him, taking his penis in her mouth still slick with her own juices. She would be able to taste herself on him. She licked his penis clean and the sight of it was too much for him to take. He held her head hard up against him and she pinched him when he thrust too deeply into the back of her throat.

He pulled back from inside her and the man on the internet would be looking at his penis, twitching against her still-shapely arse. When he came the seed spilled onto her back and she was laughing as he finished. She was turning to kiss his lips, adjusting her position on the chair.

‘Too soon,’ she said, more to the man on the internet than to Aaron. ‘I think you need to help me finish.’ She spread her thighs and he dipped his panting face towards her. The wonderful bitter-sweet taste of her. He thought of truffles and parmesan and perhaps a hint of anchovy. The salty brine of her juices. He lapped at her and it was all now as it had once been.

He noticed her hips twitching with the oncoming orgasm, slipped his fingers inside her. He liked to feel her coming around some part of him. He liked to test the violence of each orgasm, sometimes they were so hard that they sucked greedily at him, sometimes so gentle that it was like an animal sighing and turning over in its sleep.

She rocked back on the chair, her neck exposed, her face tilted towards the ceiling. Her thick dark hair spilled down and over the back of the chair. He watched as her nipples jerked tighter. He could see the beating of her heart inside her ribcage, a little fluttering of the pale flesh. A fine layer of sweat sprang up on her shoulders, a sudden scent of sex so strong that he felt his penis surge with blood again. She was more beautiful at this moment than she had ever been and he was moved to stand and press his face, slick with her juices, against her mouth. She tasted him hungrily and when there was some space for breath she gasped and told him she loved him and he hugged her so tightly that it squeezed a single tear from his eyes.

‘I love you,’ he said, ‘I’ve always loved you. I always will love you. Forever and forever.’

Aaron turned towards the computer screen and noticed that at some point the man had disappeared, turning his webcam off or changing to a different site. He assumed that the man had come and then gone: a mutually satisfying end to this first experience. He did not really care either way. He reached out and shut the laptop and hugged his sister tighter.

‘I’m sorry I fucked Trent,’ she told him. ‘I promise I’ll never do it again.’

‘Don’t say never. Don’t say it. Just tell me if you feel like doing it with him again. Perhaps we could have him over for dinner sometime. We never invite your friends.’

And here they were twinned again, Romulus and Remus. Taking their turns, sucking from the same teat.