Chelsea went on to university and did part-time modelling to pay her own way as she knew that Mum and Dad were strapped for cash – well, no one really ever plans for twins, do they? After Uni, Chelsea abandoned an academic career – which she would, no doubt, have been brilliant at – and took up modelling full-time. From then on we saw her only on high days and holidays as she flew in from one exotic location or another. She married Richard King at thirty, then after a year or so of the London scene, bought a sprawling country farm in Woburn, Bedfordshire, overlooking the ancestral seat of the Duke of Bedford and its famous deer park, where she and Richard raised pigs and chickens and did sporty things with horses that I don’t begin to understand. A few years later and her perfect two children were born to order and, of course, she regained her figure about ten minutes later.

Now my sister spends a large portion of her year out in Dubai rubbing shoulders with the fabulously rich and famous. Not that you’d guess, to look at her. The desert sun hasn’t troubled her peaches and cream complexion. Chelsea’s time is filled both at home and away by organising charity lunches and doing good in various ways while looking effortlessly stunning. As well as their penthouse in Dubai and a country seat in middle England, my sister and her husband also have a six-bedroomed villa in Tuscany and a river-view apartment in Shad Thames for when they’re over-nighting in Town on Richard’s whistle-stop business trips. Unless, of course, they choose to take a suite in the Dorchester instead, as they did last night.

‘I can’t stay this morning,’ Chelsea says apologetically. ‘We’re lunching with some friends at the Oxo Tower.’

‘Nice,’ I comment. ‘I have to get back, anyway.’ I don’t, but I’m not sure what else to say.

‘Me too,’ Lauren chips in grumpily. I know for certain that the only appointment my twin has is with her treadmill at the gym.

‘But we must catch up soon,’ Chelsea is saying. Does a shadow cross her face? ‘We’re not going straight back to Dubai. We’ll be here for a little while.’

‘Wonderful,’ I say. ‘Are you staying in London?’

‘No. At the manor. We’ll be back sometime next week.’

‘Even better. We can spend some time together. Catch up.’

‘Yes, yes. We must,’ Cheslea says, but she’s clearly distracted. And I’m well aware that she has a dozen other guests to catch up with. ‘I love you both.’

I want to tell her about our revelation last night. That all the champagne we glugged was put to good and productive use and that it’s given us the momentum to pursue perfection and fulfilment in our lives, just as she has.