M - watched porn with friends GF

I was at a friend's having drinks before a night out, it was me him and his GF. We were listening to music from his computer and a projector. He left the room to get a shower and accidentally closed the music and opened a porn tab, so we were now watching a cum shot compilation. I tried to turn it off but couldn't find the remote. His GF realised he had been wanking and told me to leave it on so he would come back and see it.
The 2 of us sat and watched for 15 minutes. And she was asking questions about it. I was horny as fuck and joked about putting a pillow over my dick. But I wasn't joking. Before he came back the projector switched it self off. So we didn't say anything to him.