While in college (m)y gf would occasionally make out with her (f)riend in front of me. It was all very cute and innocent. I encouraged this, being a horny 20 yo., and it once got everyone pretty hot. We were just playing around and the friend and I both sucked on my gf’s nipples. We watched some porn one time (early Andrew Blake stuff – so nothing too hardcore). Friend had a boyfriend at the time and I have no idea how much of this he knew about.
Once, the four of us all watched a lengthier plot based porn together after a lingerie wearing dinner. Fun times teasing and was actually a very comfortable evening but then headed our own ways to get down to business. The girls even showered together once but they swear nothing happened between them aside from scrubbing each others’ backs.
After college, once GF and I had our own place, friend ended up staying with us for a few weeks. One night, I was getting super worked up and after we said our goodnights, my gf and I started to fuck in our room. Our friend was in the other room of our 2 bed apartment and on this night I tried to see how far things would go.