‘I don’t know what to believe.’ I glance at the girls who are huddled together, engrossed in chatter in the rope nest on the climbing frame. Bobby is snuffling around the bushes close by. ‘But I suppose I have to,’ I add.

‘You mean, you have to believe him, or you have to stay with him?’ She looks incredulous.

‘Well, both.’ I know how feeble this must sound. Apparently, Penny had kicked out her husband before their son Nick’s first birthday. When she told me this, she made it sound as if their break-up was as easy as dropping off a bag of old clothes at the charity shop. ‘I cleared the decks,’ was how she described it in her usual blasé way.

‘Darling, you do know Izzy would be fine,’ she ventures, not unkindly. ‘I know it seems enormous, breaking up when you have a young child. But it can work out better for everyone, believe me.’

I nod, although the very idea of doing that to her makes me feel sick.

‘She’s a smart, level-headed girl,’ Penny adds. ‘She’d get used to the idea. Children adapt to all kinds of situations.’

‘It would be a massive thing to her,’ I murmur. ‘She adores her dad.’

‘But she must have lots of friends whose parents aren’t together,’ Penny adds, as if that would make things easier.

‘Well, yes, there’s a few.’

‘What about Maeve’s mum and dad?’

‘No, they’re very much together and blissfully happy.’ I fix my gaze upon my daughter’s cheery, animated face. I can’t even bear to think about turning her life on its head. ‘And then there’s Spencer to consider,’ I add.

‘But he’s an adult, leading his own independent life!’

‘He’d still be upset. I’m sure he thinks me and his dad are pretty solid, you know?’

‘Yes, but it’s not about them, is it? It’s about you, and what you want. And look what Andy’s done to you.’

‘Yes, I know,’ I say, unconvincingly. But we’re a family, is what I really want to say, and I’m not sure I can throw away these twenty-five years. Although I’m still angry and hurt, I’m trying to do the right thing here. I don’t know how to explain that to Penny without it sounding as if I somehow disapprove that she left her son’s dad. In fact I think she was far braver than I could ever hope to be. Right now, I feel terrified.

‘Pen,’ I say now, ‘can I ask why you split up with Nick’s dad?’

‘Oh, I’ve told you all that already,’ she says quickly.