So I let myself in to a dark empty house. I went down to the kitchen and cleared things up. I turned off the lights and went upstairs, picking up various discarded garments of clothing en route. In the bathroom I washed my face and brushed my teeth, cleaning the sink with the other hand as I did so. I went back to the bedroom, drew the curtains, undressed and climbed into our huge cold bed, and lay there in the darkness listening to the noises of the house bereft of inhabitants; it felt strange, alien, lacking.

Yes, everything had changed now.

Annie had finished all the popcorn and we had slunk further down the sofa. We were sucking on Fab ice lollies and watching the climactic moments for poor Buzz and Woody trying to escape from the recycling machine, when I felt my phone buzz in my back pocket. I took it out. Karl’s name was on the screen. He was taking clients for dinner in Soho; presumably he’d finished early and fancied a pint. I swiped and answered. ‘Hello, love?’ I said.

I couldn’t hear properly because of the film. I covered my ear. ‘Hi!’ I said. He didn’t answer.

‘Hello? Karl?’ I said. I could hear him faintly, as if he were a long way off; I thought he was laughing. I unhooked Annie’s legs from me and got up from the sofa, phone pressed to my ear. I went into the playroom. ‘Karl?’ I called. And then I shouted, ‘Karl!’ But still he didn’t hear me. I listened carefully.

‘Oh, baby,’ he said. I thought he was messing with me.

‘Yes, baby?’ I said.

‘That’s it, baby,’ he said. He wasn’t messing; he sounded really intense. ‘Mmmm . . .’ he went, as though he was eating something delicious; pistachio ice cream, perhaps – that was his favourite. Yes, that’s what I honestly thought. And as a greasy feeling of dread slid through me from the pit of my stomach, my head kept whispering that this was the deal we had made.

‘Uhh . . . yess . . . that’s good . . .’ He wasn’t eating ice cream; it sounded more like kissing. ‘So good . . .’ he moaned.

Wrong again, not kissing.

‘Oh!’ he said. ‘Oh . . .’

No prizes here: those were the undeniable sounds of fellatio.

I know I should have just put the phone down, but there was something mesmerizing about it. I couldn’t. I stood there in the playroom, my foot on a Twister map, one hand holding a Fab lolly, the phone pressed to my ear, listening to my husband getting a blow job, unaware that I was in his back pocket, my ear and her mouth only inches apart, my heart punching against my breast, as it is even now as I write this. And still I listened.

‘Oh, you angel,’ he said.

He used to say that to me.

‘Oh, you sweetheart,’ he said.