Hey all, I am looking for a story that I read and commented on on reddit. The story was about a guy with a live in girlfriend where her sister or friend introduced her to a guy and they hit it off and flirted the whole night. This was a multi part story where a few parts were from her perspective and the guy had access to her texts, photos and videos and got off on her cheating without her knowing.

Eventually they go on a big trip with a group of friends and she ends up fucking the other guy almost nightly; the boyfriend helps to manufacture situations where they can fuck so that he can jerk off to it.

It turns out that he eventually called her out and they ended up breaking up and she ends up with the guy she had the affair with. And apparently she and her new boyfriend have actually had sex in front of him.

I just want to find this story and check for any updates because it was pretty hot but also kind of messed up.

Edit: thanks to your help I found it. Much appreciated!