Doesn’t she look beautiful?’

Vicente has slipped in beside me at the party and we’re both admiring Mum as she chats to some of her arty friends. I nod in agreement. Mum’s in a vintage floor-length Halston dress she’s had since her modelling days, and a long gold necklace with a large topaz rock at the bottom of it. Even without much makeup – she never wears more than lipgloss nowadays – she’s still pretty stunning. The soft light helps, of course. I enjoy teasing Mum about her age, but actually, it doesn’t bother her. She says she’s having more fun now than she did when she was modelling. This can’t be possible, of course. She just sits around working most of the time. But at least she doesn’t complain about it.

Vicente is not bad himself. Jet-black hair. Angular face. Granny wasn’t joking when she called him classically handsome. But more than that, he is totally charming. He’s been charming all evening and he keeps it up as he guides me onto the dance floor and makes a decent job of grooving on down to some Rolling Stones that Harry has put on in his honour.

‘Mum loved the roses,’ I shout across at him. Harry is not shy about loud music. The neighbours have been round to complain twice already. I think even the walls are rattling.

‘Good to hear it,’ Vicente shouts back. ‘That reminds me . . . do you mind?’

He eases his way across the dance floor and invites Mum onto it. I don’t mind, really. They make such a good couple.

Crow and Jenny are clustered in a corner. I go and join them and we all watch Mum and Vicente doing their thing.

‘They’re naturals, aren’t they?’ Jenny shouts across at me.

I nod.

‘You’d think they’d been together for the last twenty years.’

I nod again, hoping that my sudden blurry vision is due to standing too close to a speaker, and nothing else.

‘Why didn’t they stay together, anyway?’ Jenny asks.

I want to say something, but I’m still trying to find the words when a red-faced man suddenly appears in the middle of the dance floor, shouting and waving his arms around in an extremely unfunky way.

Harry, shocked, turns the music off.

‘I SAID,’ the man bellows, going a dangerous shade of maroon, ‘TURN THE BLOODY MUSIC DOWN OR I WILL SUE!’

As the room is actually totally quiet by now, apart from him, he surprises even himself with his personal volume. Fifty pairs of eyes are looking at him. He coughs.

‘I’m sorry,’ he says. ‘Let me rephrase. Thank you very much for turning the music down. Now, if you’ll excuse me, I’ll get back to my dinner party.’

‘Oh!’ Mum exclaims, her hand going to her mouth. ‘You were having a dinner party? I’m so sorry. I had no idea. What can we do?’

‘Nothing,’ the man says flatly. I recognise him as our next-door neighbour, the grumpy guy who moved in last year. ‘My more sensitive guests have gone home. The others are nursing Nurofen in a darkened room. I should get back to them. Oh, congratulations, by the way.’ He says this to Harry. ‘I heard the news. Hard to miss it. I assume this means you’ll be moving out?’

Harry grins, looks sheepish and nods.

The man smiles with grim satisfaction and disappears. Harry turns the music back up to half its original volume.

Jenny, thank goodness, forgets what she was talking about and instead goes back to complaining about how Edie (not here – debating rehearsal) never has any fun any more, and how amazing the latest styles look on all the passing models.

‘By the way, I like your outfit,’ she says to me eventually, as an afterthought.

I know she’s being polite. I’m in a black knitted dress I’ve borrowed from Mum. It’s skin-tight Azzedine Alaïa and totally fashion-safe. But it was made for a taller person than me and, bizarrely, makes me look like a slightly fashion-conscious nun. Better than the kimono, but not one of my greatest moments.

‘Doesn’t Isabelle look incredible?’ Jenny adds.

This is easy to agree with. My future sister-in-law has turned up in an oversize white cotton shirt worn as a dress, with a seashell necklace and a dog lead worn as a belt. Oh, and a pair of sculpture ankle boots borrowed from the Dior couture collection, to show she’s making an effort.

Me, Azzedine Alaïa – nun. Isabelle, white cotton shirt – sex goddess.

I love Harry, and Isabelle’s adorable, but couldn’t he have gone out with a normal human, just for once?