Leaning towards her while she flicked between sites, I smelled her perfume and was thrust back in time to an afternoon we’d spent in bed together watching The Graduate and having sex that, not unusually, had been more like a lesson than anything else, Karen giving me gentle instructions as I went down on her: where to position my tongue, how firm, how fast, what to do with my fingers, and so on.

‘Andrew? Have you zoned out?’

‘Huh? Oh, sorry. I was just remembering something.’

She arched an eyebrow. ‘Something good?’

I definitely must have blushed this time because she winked at me and said, ‘Not the kind of thing you would want to tell your girlfriend about?’

I didn’t reply. I felt guilty enough as it was. I definitely didn’t fancy Karen anymore, and not just because the light that shone from Charlie cast all other women into shadow, but because that had been a period of my life that I wouldn’t want to return to. I was a proper grown-up now.

‘Does she know you’re here?’ Karen asked.

‘Yeah, of course. Why wouldn’t she?’

She shrugged. ‘I don’t know. Some women get funny about their boyfriends meeting up with their exes.’

‘Charlie’s not like that.’ Plus, I almost added, I wouldn’t really class you as an ex.

‘That’s good. There’s nothing that kills a relationship faster than jealousy. It’s why I split from Yuri.’ That was her long-term partner. ‘The last six months with him . . . well, I learned why they call it the green-eyed monster.’

I left a little while later, having agreed to show her a first draft the following week, and hopped on a bus to Farringdon, where I had arranged to meet Sasha.

The thing was, Charlie had been a bit weird when I told her I was meeting Karen to talk about designing a website for her.

She was getting ready for work, putting on her make-up. I loved watching her, a mug of coffee steaming in my lap, bright winter sunshine lighting up the flat.

‘What?’ she had said. ‘You mean the Karen you were telling me about? Your former lover?’

I cringed. ‘I hate that word.’

She turned from the mirror, eyeliner pencil between forefinger and thumb. ‘She wasn’t your girlfriend though, was she? You said it was purely a sex thing.’

I put my coffee down. When I had told Harriet about Karen, towards the start of our relationship, she had reacted in a way that had surprised me. She didn’t care about any of the other girls in my past, but she took an instant dislike to the idea of this older woman whom I’d slept with but who had not been a proper girlfriend. She occasionally mentioned her during arguments, when she would shout, ‘Why don’t you go back to the Old Slapper?’