‘It’s for such a good cause,’ Stacey says, winking at me.

At the next table, Tom roars with laughter at something Harper has said.

‘By the way, Millie,’ Stacey says, ‘I have a few pieces of furniture we can’t take with us to our new apartment, and I wondered if you’d be interested in having me leave them behind? That teal Julian Chichester cabinet in the sitting room, and the Agostino mirror. They’re simply too big.’

‘Are you sure? They’re so beautiful,’ I say.

‘You’d be doing me a favour taking them off my hands. In fact,’ she adds, ‘why don’t you come and take another look at them and then decide? Maybe Saturday morning? Felix makes a mean mimosa.’

‘I could do Sunday,’ I say. ‘I have surgical rehearsal this Saturday.’

‘Sunday works.’

Felix leans behind the man seated between him and his wife. ‘Stop it, Stacey,’ he says.

His tone is cold. I don’t know if he objects to the brunch invitation in general, or me in particular.

Michèle launches the live auction, perfectly timed for this point in the evening when the guests are nicely lubricated. The bidding is lively and even raucous at times as donors compete to flex their philanthropic muscles.

I act as a stalking horse on a number of big-ticket items, drawing out the high rollers and gracefully conceding defeat when I’m outbid. I’ve already made a private donation: when Tom gave me my Audi, I made a matching gift to the hybrid OR, though I didn’t tell him that. We can’t quite afford it, but I wouldn’t have been able to drive the car with a good conscience otherwise.

At the adjacent table, Harper squeals when she wins a photoshoot with society photographer Hugo Burnand. ‘Kyle, he took the wedding pictures of Prince William and Kate Middleton!’ she cries. ‘And now he’ll be taking pictures of us!’

A couple of well-known television personalities approach Michèle at the podium to make pre-arranged ‘spontaneous’ offers to share their talents or open their homes, the sequence carefully choreographed to make other guests feel like they’re in at something rather special and unexpected.

One excitable woman bids five figures to be a guest weather-girl on morning television. Another buys her daughter’s name for a character in a bestselling thriller writer’s new novel. A champion show jumper stands up at the back of the ballroom, and offers riding lessons on the horse she rode in the Olympics.

‘I’ll pay double if you take the place of the horse!’ a man calls.

Laughter.

Harper leaps to her feet, swaying slightly. It’s clear from the feverish light in her eyes that she’s very drunk. ‘Who’ll bid a thousand pounds for private training sessions with Kyle?’ she cries.

There’s a slightly sticky lull.

‘You can be on our vlog, too!’ Harper adds.