‘Ralph,’ I said, shaking my head, looking him in the eye. ‘It doesn’t add up. It doesn’t make sense. You know there is never, ever, any such thing as no strings attached. There are always strings. No free lunch. You must have realized. Even the law has changed, so children can find their own birth fathers, even if they were student sperm donors doing it for beer money or whatever. There’s traceability, and all this stuff about people being entitled to their genetic inheritance, why did you think these rules wouldn’t apply to you? Because you’re so bloody marvellous?’

Ralph blenches.

‘I can’t believe you took such a big risk with our whole family life, and your children’s happiness, just for a few hundred thousand pounds.’

‘I made a mistake,’ he said. ‘I thought I could trust her to keep it between us, as she promised, and swore, and only ever between us. And I felt sorry for her. There’s stuff about Clare, I don’t know if you know…

Ralph swallowed. He looked stricken. As I well know, Ralph’s first rule in life is Never say anything to anybody, and his second rule is Never trust a woman, because they can never deliver on the first.

‘You must believe me, darling. I did it for the financial reason, there was absolutely nothing – nothing – between me and Clare, but it was terribly hard to refuse her, after what she said about Gideon. I just felt that I wanted to show her that men weren’t all complete shits, and I’ve ended up being one myself.’

Then he repeated miserably, as if he couldn’t believe he had fallen for them at the time, some of the other specious and manipulative arguments Clare had used to persuade him to part with his DNA. As he spoke, I realized it was a stroke of luck for Clare that Ralph had somehow managed to avoid the endless discussions about the sperm shortage on Woman’s Hour. It just wasn’t his thing. Trade row between Russia’s Transneft and the nation of Belarus, hell yes. Earnest debate about the identification of donors’ body fluids, not in a million trillion years.