When our older sister sees us, she makes her way to our table and kisses each of us in turn on both cheeks. Chelsea doesn’t look like she’s had a night on the tiles – she looks like she’s had a full eight hours’ sleep and possibly an oxygen facial since we last saw her, so radiant is she. I’m glad that I put on some slap, a luxury that isn’t normally seen at breakfast – even though I did it because I thought Jamie Oliver might still be here.

Our sister puts a hand on each of our shoulders and squeezes affectionately. ‘I hope that you both had a great time last night.’

‘It was wonderful,’ I gush. ‘I live my life vicariously through you.’

I always look at my elder sister and envy her. She is cool, calm, collected in every circumstance. Her husband is obviously a sex god as she permanently carries the look of the orgasmically sated. Not for her the once-a-fortnight fumble that I’ve sadly grown accustomed to, I’ll bet.

My niece and nephew are model children and are already seasoned travellers. Sophia is six and is an accomplished pianist and a promising ballerina. Henry, at the age of four, is fluent in French, a star at his stage school (he is the cherubic smiling face of Wheety Bites in the television advert), plays the violin and is probably now a Black Belt in karate as well, as I haven’t had an update on their progress for the last couple of weeks. Some days, I even daydream that they’re my own children. But then Chelsea would never have anything that didn’t come up to scratch – particularly not her kids. Even the dog’s a naffing top-ranked pedigree.

Yes, our sister’s life is perfect in every way imaginable. I don’t know why, but Chelsea’s never had to try hard like Lauren and I have. And we try very hard not to resent her for it – but we do.

‘It was cool,’ Lauren mumbles, pushing in more toast.

‘Look what Rich bought me.’ Chelsea flashes a sparkling eternity ring encrusted with diamonds. The brightness of it makes us both wince.

‘Gorgeous,’ I say.

‘Humph,’ Lauren manages.

Chelsea looks across the room to where her adoring husband is reading The Times at their table, a contented smile on his face.

Lauren and I were both pretty rubbish at school, whereas Chelsea was always top of the class. She was the straight A student while we, The Terrible Twins, had a permanent appointment with detention. We were both high spirited and, as twins can, egged each other on. It wasn’t that we were naughty, it was that we were particularly bad at not getting caught.