The first fissure in the smiley happy coalition appears and, as the bookies predicted, it is between Samantha and Miriam.

It was all Clegg's fault - inevitably. It was he who had insisted that "the girls" get to know each other, who had talked euphemistically about mixing work and pleasure, who, by brute persistence, had wheedled an invite from a wary Dave for his entire family to spend a weekend at Chequers - with Theresa May and me making up the numbers.

The Cleggs, rudely, were late. Although arguably not late enough, for it would have been better all round if they had turned up on, say, Monday. When I arrived, Samantha was pacing up and down the hall and Dave was making a poor job of placating her. "Just one thing I forgot to tell you, poppet." "She's not a fucking veggie, is she?" "No, she's a high-flying international lawyer." "So what? We could all be high-flying international lawyers. All it takes is remembering a few books." "Yes, yes, sweetheart, it's just that Nick texted me . . ." "It's texty wexty with Nicky Wicky now, is it?" "Anyhow, Miriam was wondering if we could all have supper early with the kids to free up a few hours for her to catch up with her heavy caseload."

"Pwwugh." "What do you mean, pwwugh?" "What I mean is that Carmen Miranda is welcome to eat fish fingers with the kiddies at six but dinner for the adults will be served, as ever and sans kids, in the dining room at 8.30."

And at that moment the Cleggs came through the door, Miriam, rather ostentatiously, holding two lawyer's bags and Nick struggling with the offspring.

It was just the six of us for dinner. And things would have been even frostier, had I not had the wit to remove, just before the Prime Ministers entered, the tub of lard that Samantha had positioned on the place laid for Miriam. As it was, we all seemed to spend a lot of time listening to Theresa.

Nor was Sunday an improvement. Matters worsened considerably when, with Dave and Nick being photographed sitting on a bench on the lawn, Miriam working, Samantha cooking and Theresa left in charge of the children, an accident happened.

Who was to blame, we may never know. All that is certain is that one of the Clegg boys required stitches. And while they were being sewn, an extremely bloody cross-cultural childcare argument kicked off, which the husbands - not a good harbinger - failed utterly to mediate.

The whole shebang rather put the kibosh on Sunday lunch.