I feel sick. My stomach turns as I realise what I’m looking at. It takes several photographs to understand the full picture, but it’s pretty clear. It’s made all the more difficult because our sexual repertoire narrowed after we married. Before we walked up the aisle we tried everything at least once, but after the honeymoon you tailored our sex life to suit yourself. I’d often plan a sexual adventure, something new, fantasise all day about it, buy new underwear and try it on with you, only to be rebuffed and coerced into the ‘usual routine’.

I blamed it on you being tired, but now I know you were fucking tired. Very tired. Worn out, in fact, from fucking your girlfriends and engaging in what now appears to be oral sex in public places. I can feel my temper rising again and before I know it I’ve got Julie’s Facebook profile up in front of me.

I can hardly see through the mist of tears, but there she is, her and Francis and two little white dogs, as neatly coiffured as she is. Smiling, ever smiling, that perfect mouth that’s been around my husband’s cock.

Monica isn’t friends with Julie so this is going to be more difficult to rationalise. But you’re still friends with her. I can see from your profile that she’s wished you a happy birthday and that there’s a winking smiley. Of course there is. Monica isn’t friends with you now either. Not to worry, though. Plenty of Monica’s friends are friends with you, so hopefully they’ll see the blurry-at-first picture of Julie’s head posted on Monica’s timeline. Then, when they realise what it is, they’ll alert you, won’t they? Well, the ones who know you are a cheating bastard will, anyway.

That horrible feeling that everyone knew except me creeps over me. It seems impossible that all your friends were oblivious to your behaviour. Some of them must have known but just didn’t want to get involved. But they will on Facebook. Just to be sure, Monica has also shared the picture with Julie in a private message.

The impact is almost immediate. The photo is shared five times and I receive a message from Julie.

I know this is you, Caroline. I’m calling the police. Jack’s right. You’re completely crazy.

I close the laptop and finish my coffee. Then I hop back onto a tram and travel around the Metrolink for the rest of the evening, watching the carnage as all your friends realise what the picture is and share it far and wide. I think some people are really enjoying this. Some fickle friends who were never sure if you were fucking their wives and girlfriends or not.