For the first time ever Leo actually gave me a lift home after school. I had waited behind in the school library after most people had gone home because I wanted to avoid everybody on the way out. Lunchtime had been bad enough. Three people had asked me if I’d seen Leo in his boxers, and Hanna and Clara just seemed to crease up in giggles every time they looked at me. No way was I letting myself in for any more of a grilling. Leo came into the library to give back some books, saw me sitting there on my own and immediately suggested we should head off together.

‘How was your day?’ he asked me in the car.

‘Terrible,’ I replied. ‘Yours?’

‘Ditto. I ended up shouting at one of the other teachers in the staffroom.’

‘Really? Which one?’

‘It doesn’t matter – the point is it happened just as Mr Jamieson was walking in to get his morning dose of caffeine.’

‘Oh no! What did he say?’

‘He said, “Excuse me, children, is this the playground or the staffroom?”’

‘Ouch!’

‘I thought so. I started to explain and he told me to save my breath to cool my porridge. I thought he was going to call me “laddie” but I was spared that, thank God!’

‘Oh, Leo!’ I started to laugh.

We were driving back past the little row of shops near our school when we spotted Zack coming out of the pet shop.

‘Zack is the only person who’s acted normally towards me all day,’ I told Leo. ‘He kept me company at lunchtime, though I had to hear all about his pet tarantula. Apparently Tallulah is an excellent “starter spider” and just the kind of tarantula I should get if I ever fancy having one as a pet!’

Leo laughed until he looked in his rear-view mirror and saw my brother coming out of the pet shop behind Zack.

‘I thought he was meant to be sick,’ Leo murmured, screeching into the nearest parking space and exiting the car in a matter of seconds.

I waited where I was and the next thing I knew Sean was climbing grumpily into the back seat as Leo slammed the door shut behind him.

Needless to say, Leo was furious, and after he’d pulled out on to the road again he demanded to know why Sean had taken the day off school if he was well enough to go out on a shopping trip with Zack.

‘I felt better this afternoon. What’s the big deal?’ Sean protested, at which point Leo nearly crashed into the car in front, which had stopped at a pedestrian crossing.

We all stayed quiet after that.

As soon as Leo parked up outside our house, Sean leapt out of the car and rushed to the front door to let himself in. He went straight through to the kitchen and I quickly followed, seizing the opportunity to speak with him alone while Leo was still fetching in his stuff.

‘Sean, what’s going on?’ I asked as I watched him fiddling around in the freezer and eventually taking out an ice lolly.

‘I just didn’t want to face everyone after that whole nightmare with the box on Saturday night. I felt … I don’t know … a bit of an idiot.’

I was surprised. Sean almost never talks about his emotions, or admits to feeling embarrassed.

‘I hate to tell you this,’ I said slowly, ‘but everyone’s over that already. Lily told someone about Mum and Leo. Now the whole school knows, even the teachers. That’s what everyone’s talking about.’

‘Oh my God,’ he said disbelievingly. ‘I bet the whole school is loving that!’

‘It’s been awful,’ I said. ‘Even the Year Elevens have been giving me funny looks.’

Sean laughed. ‘They’ll get over it. You know all the girls have got massive crushes on Leo, don’t you? They’re probably dead jealous of Mum.’ He frowned slightly. ‘But listen, I’m surprised at Lily telling anyone. I didn’t think she’d do that to you.’

‘Neither did I.’ I lowered my voice. ‘Sean, what were you doing in the pet shop just now?’

‘Tell you later. Right now I have to get upstairs and start being a good little sick boy again before Leo gets on my case.’

‘Too late for that, Sean,’ Leo said as he entered the kitchen behind us. ‘But you can certainly go up to your room and make a start on all the homework I managed to procure for you.’

‘Homework? Come on, Leo, give it a break, can’t you? I mean, don’t tell me you never pulled a sickie when you were a kid!’

Leo looked surprised. ‘Actually, Sean, I never did. Both my parents were teachers, remember. My life wouldn’t have been worth living if I had, especially as my dad was best mates with my headmaster.’

‘Oh yeah … I forgot … sorry.’ Sean actually smiled. ‘You know, that really explains a lot. Keep reminding me so I can make more allowances for you!’

And he disappeared upstairs with a cheeky grin on his face before Leo could respond.

Later that evening I walked in on Mum and Leo while they were discussing my brother in the kitchen. It wasn’t a private discussion. Sean was right there, leaning against the kitchen counter looking sulky.

‘You can’t be serious about just letting this go, Annabel!’ Leo was saying. ‘You just heard him admit that he lied to you about being sick this morning, which is bad enough … but then to have the brass neck to go out and meet up with Zack the second school’s out … He’s lucky it was me who spotted him and not Mr Jamieson.’

‘I get what you’re saying,’ Mum replied. ‘But it’s done now. I just don’t see what else you want me to do!’

‘For God’s sake, Annabel! It’s surely not that hard to come up with some kind of consequence! You can’t just let him bunk off school!’

Mum looked very angry suddenly, as if Leo had hit on a raw nerve. ‘Hey, don’t you start with the criticism,’ she snarled. ‘I’ve had a bellyful of that already today!’

‘What do you mean, Mum?’ I asked – then quickly wished I hadn’t as she turned to glare at me.

‘What do you think I mean?’ she snapped. ‘Miranda is still furious with me about your party. She says I’m obviously failing to supervise the two of you adequately and that I need to address it pronto.’

‘But that’s not fair, Mum,’ I protested. ‘The party wasn’t your fault.’

‘Yeah,’ Sean agreed. ‘Don’t listen to Miranda, Mum. It’s none of her business anyway.’

‘Oh, I don’t know about that, Sean,’ Leo put in brusquely. ‘If news of your party gets out it will be very much her business that will suffer, I should think.’

‘I’m dealing with this, thank you, Leo!’ Mum jumped in sharply. ‘There’s no need for you to interfere.’

‘Oh yeah?’ Leo sounded annoyed. ‘Well, maybe you should make up your mind, Annabel! Because one minute you’re encouraging me to be a father figure to the kids and the next you want me to butt out completely. You can’t have it both ways. It’s confusing for me and it’s confusing for them!’

There was a bit of an awkward silence while they glared at each other. Then Mum swore under her breath and stormed out of the kitchen.

It was what happened next that really scared us.

Leo stormed out of the kitchen after her, but instead of following her upstairs, he slammed out through the front door without even saying goodbye.

That night I found it hard to get to sleep, and even when I did, I ended up waking up in the middle of the night in a panic. I lay awake again after that, trying not to think about Leo and Mum. I was really worried. It’s like Granny says – Mum’s pretty rubbish when it comes to lasting relationships. And if she didn’t do something to fix this, I was terrified that Leo would leave us for good.

Leo wasn’t there when we got up the next morning, which I guess shouldn’t have been surprising, though I have to admit I’d been really hoping he’d come back at some point during the night. Mum hardly even looked at us while we ate breakfast, and for the most part she seemed lost in a world of her own. I knew she was feeling down, and probably upset about Leo, and usually if she feels that way she’ll talk to Miranda about it when she gets to work. But thanks to us, she couldn’t even do that at the moment.

‘You know, I’m really sorry about the party, Mum,’ I said earnestly, feeling guilty for letting my desire to impress Rafferty override everything and everyone else.

But Mum still didn’t speak and I had a horrible feeling that she wasn’t even listening as she carried on sipping her coffee in silence.