An excruciating pause. Of all the people in the world who I’d want to know what I’ve done, Dad is the last on the list. I squirm.

‘I’m sorry, Dad. It was thoughtless of me. I just didn’t want to worry you.’ That’s a fib. It’s not about them, it’s me: I couldn’t face the humiliation. ‘I’ve been overwrought. The impact of Clare.’ Despite myself, there’s a catch in my voice. ‘And, well, I behaved a little unprofessionally. I was a bit over the top in an interview.’

Silence. ‘What did you do?’

I hadn’t expected such a direct question. It isn’t typical of our relationship, where we talk about safe things – such as whether Spurs should be ecstatic or worried that arch rivals Arsenal have appointed an eccentric French economist as their new manager – but never explicitly about the important stuff, let alone anything that might involve feelings.

I cast about in my mind for a sanitised version that’s convincing, even one that might cast me as the brave lefty journo putting the corrupt Tory minister on the spot. But even as I start formulating the white lie, it dies inside me. I can’t do it. I don’t want to do it. For reasons I can’t explain, I need my dad to know how badly I fucked up.

‘I accused the Chancellor of having an affair with Clare.’

There’s a long silence. What have I done? I begin to panic. Dad’s well into his sixties. He’s fit, but his blood pressure is too high. Has the shock caused a thrombosis? I should have dissimulated, not broken the habit of a lifetime.

And then I hear something that takes me by surprise. It starts out gently but is soon full throttle. Dad is laughing. Not in a mean or nasty way. But deep from the belly, as though someone has told him the most hilarious joke. It’s the kind of laugh I haven’t heard since the two of us – well, the four of us – watched Morecombe and Wise together in the 1970s. In between the roars, he manages, ‘Why on earth would you think that? Keith Kendall’s rather more likely to have an affair with you than with your sister.’

What?

All I can manage is, ‘You knew?’

‘I was at university with him, remember?’ Dad says. ‘He wasn’t out, to use today’s term. But you know what it’s like at college. No one had secrets. He had a fling with a lad from my corridor, who also eventually got married and went on to be a professor of history at Harvard. I shouldn’t tell you this, but when I was very drunk one night I actually necked with him at a party.’

Dad! Too much information!

‘It’s all right,’ Dad assures me. ‘It was before I met your mother and she knows all about it. She thinks it’s terribly funny. But what on earth made you think there was anything between him and Clare?’