And the latest one had indeed been easy, and the plate had been at a supper party at the Taylors’, who, it occurred to me now, as I drove home, were not only friends of mine, but of Helena’s, too. Michael’s attraction to Ingrid, a Swedish interior designer, had been so blatant that Millie Taylor, our hostess, had even tried to intervene. When Michael and Ingrid had stayed at the table long after everyone had retired for coffee, she’d hastened back to join them, pink-faced with embarrassment. Later, I’d texted Millie for Ingrid’s number, on some pretext about wanting to re-do our kitchen in a Scandinavian style. I knew she knew, but frankly, at this stage, I didn’t care. That’s how low I’d sunk. It had no doubt gone straight back to Helena.

Actually, that’s not true. Of course I cared, it was totally demeaning; but it was necessary if I wasn’t to be further humiliated. I sighed as I joined the heavy M40 traffic back to London. And I’d hate you to think this was a constant surveillance mission, a never-ending stealth operation. It wasn’t. Michael and I had been married for twenty-eight years. We had two grown-up children, and I could count on one hand – well, all right, two, but only just – the times I’d had to step in and … you know. Operate. And neither was I alone in this. Melissa, my best friend, did it too. Turned a blind eye. Or at least she had done, until she’d failed to observe the cardinal rule, if you want to remain married, which, trust me, many women, for a variety of reasons, do. She’d hurled his laptop – on which she’d found the evidence – out of the bedroom window and deposited his clothes in a bin bag on the steps of his girlfriend’s house in Chiswick. Except they weren’t in the bag, they were scattered all over the steps, cut into tiny pieces. Melissa lives near me now, across the road in Fulham. In a tiny rented flat she can barely afford. Dominic, her husband, moved into the large Chiswick house belonging to his girlfriend.