By lunchtime the next day Ben questioned why I was so glued to my phone and I had to lie on the spot. The best thing I could come up with was a dating app, which I instantly regretted as his face darkened. I’d never been good under pressure, especially at lying.

In truth, I couldn’t stop watching the window into Ian’s life, although there had barely been any activity; only a couple of flashes of him walking past early this morning, wearing his rugby kit. I knew he’d be out most of the day. Being a voyeur was addictive. In the end I forced myself to put the phone down.

‘What are you doing this weekend?’ I asked Ben.

‘Not a lot. Amy is on a hen weekend in Brighton, so I’ll be just chilling. How was your date?’

‘All right.’ I didn’t want to elaborate; Ben would see straight through me. Thankfully he didn’t push for more information.

‘Fancy a movie and a takeaway tonight? Or I could cook, we haven’t had a themed night in a few weeks.’ No, we hadn’t, not since Amy came along anyway.

‘Takeaway would be good,’ I replied.

Whilst Ben was out collecting the curry, I opened the app to see if Ian had returned and almost jumped when I saw him sat on the sofa, a laptop across his knees. The PetCam had a microphone you could talk through as well as playing audio. When the app was opened, both features were set to mute. I unmuted the audio, so I could listen. Sounds of sex filled the room, slapping of skin on skin and a woman squealing. I baulked, wrinkling my nose. He was watching porn on his laptop. Not that different from other men after all. Cheeks flushed red with guilt for prying, watching his arm jolt up and down as he pleasured himself, I couldn’t tear my eyes away. After a minute, when I was just about to close the app down, the squeals turned to screams. A different sound came through the speakers. Crunching of bone and swear words spat venomously. On the laptop screen, it looked as though the man was now beating the woman. Something which had started out as sex had turned into a vicious attack. She was crying for help as punches rained down on her. My eyes brimmed with tears, the phone quivering in my hand, but I couldn’t wrench myself away from the horror. Ian’s arm was moving faster, his excitement palpable. It sickened me, how could someone enjoy watching such violence? Ian groaned, and I guessed he’d ejaculated. My throat constricted, and I thought I was going to be sick.

I didn’t hear Ben enter the flat. When a voice came from behind me, I jumped out of my seat.

‘Are you watching porn?’ he asked, the corner of his mouth turned up into a half-smile.