I had sex with my befriends boyfriend !!!?

So I had a party at my house and me best freind came with her boyfriend ……… she passed out in the couch and me and Aaron (her bf) where talking having a fun time. He asked me to dance so we did when the party was over he asked me if he could stay a little longer and I said sure. So then we started kissing then making out then we ended up having sex in my room. my friend was still asleep but idk I feel really bad for having sex with her bf but in a way I don’t regret it … what should I do !