‘Many times. It’s part of the pattern, isn’t it? As you say,’ Rose says, glancing up as a car with a throaty exhaust pulls up on the gravelled forecourt, ‘she has to have what you have.’

‘God knows why,’ I say, watching Ralph unfurl himself from the Ford Falcon, clad in linen trousers and a long-sleeved cornflower-blue cotton shirt and looking brown, like something out of a Hollywood comedy with Peter Lawford, or Cary Grant. The door makes a satisfying noise as it slams shut.

‘So, presumably, as soon as she found out you were pregnant, she had to be pregnant too. You were having another baby. So she had to have another baby. It’s very logical. Even though you’re no longer neighbours, she still has to keep up with you. There’s only one thing I don’t understand. How did she know you were pregnant?’

‘I told her,’ I say, feeling silly, remembering the long email I sent her back in January, which I regretted as soon as I’d pressed send. ‘Actually, hold on, Rose. That’s a very good point. I just told her I thought I might be. I never actually told her I was. Did you tell her?’

‘No way,’ protests Rose. ‘I didn’t know her that well at Cambridge, and that was twenty years ago. She got in touch with me, remember, and when she came to the Dairy, I didn’t even know you used to know her too and were on the same communal garden till you turned up that day, and she was there. I’m not exactly going to share the most intimate details of your private life with Ralph with an acquaintance, am I? The cow,’ says Rose cosily.

We watch Pierre and Ralph – neither of whom ever lie in the sun, or dip a toe even into the pool, expose their limbs, or remove their shoes and socks – go into the house, with the English newspapers tucked under their arms. In an hour, it will be time for a late lunch on the terrace.

‘Well, I don’t know how she found out, but she picked the wrong couple to mess with,’ I say, stoutly. ‘I don’t see how she thought she could swing it. You don’t repay a, um, happily married man who has helped you out of your fertility black hole out of the, ah, goodness of his heart’ (I gloss over the financial incentives, which were not inconsiderable) ‘by threatening him that you will tell his, er, innocent wife all about the paternity of your son unless he provides you with a second baby, do you? It doesn’t work like that. Ralph is impervious to any sort of emotional blackmail – believe me, I’ve tried. He just welcomes it. As a test of his moral fibre.’ I sink back.