‘We were engaged. Anyone else? Come on, girls. Let’s tell the world what Jack Atkinson’s really like #cheatingbastard.’ I post the picture and tag Jack, Lucy and Kieron. I wait ten minutes, sipping a frothy cappuccino, and congratulate myself for not choosing vodka. It’s nice here, in front of the fire. I feel a little sleepy, but I need to stay awake. I’ve dismantled my phone so when DS Percy rings me she will get my answerphone.

I log into frigid Lorna’s fake profile and post a comment under Alicia’s post: ‘Me. He wanted more than I was prepared to give him #cheatingbastard #allgirlstogether.’

Then I log into Louise Shaw’s profile. I post another comment on Alicia’s thread. It’s a photograph of her and you. You’ve got your hands on her breasts and she’s pouting.

Lots of people are admiring your photography skills with your lovely new camera. I Google our insurance company, the one we used to use, because I changed it when you left. I go to their contact form and enter your details, our old address and your new address. Then I explain how the ring belonging to your wife that you said was stolen wasn’t stolen after all and that you actually gave it to your mistress. Oops. Then I attached the photograph of Alicia wearing the ring and press submit.

When I go back to Facebook, incredibly, Katy Squires has posted her own photograph. I haven’t checked her out yet so I’m totally not ready for this. She’s standing beside a Christmas tree and I check the background to make sure that it isn’t my house.

It isn’t. It’s a Victorian-style lounge with a Chesterfield and a piano in the background. You’re standing behind her. Your hands are stretched around her pregnant belly. I feel momentarily sick, but remember that I’m doing this so I know everything. I scour the picture to try to find some clue to how long ago it was taken. She was at the end of the journal, near to last.

I find her Facebook profile and there she is, with a small child. He’s all over her Facebook. Jamie at playschool. Jamie in the snow. Jamie with a dog. Jamie with a bike. I scroll down and down through her photographs and, finally, about four years ago, Jamie with Daddy.

There you are, Jack, in the hospital, holding Katy’s baby. I click through the photographs, almost blind with tears. This was in the years we were together. All the times I asked you if there was someone else, if things were wrong between us. You just stared at me and suggested I go and get some medication. That I was imagining it.