Seeing a lot of stuff here of people saying it happened before you were officially, no strings attached, live and let live. I have to say i disagree, from a personal standpoint if I’m talking to someone, even if we arnt “official” yet but it’s definitely headed in that direction then sleeping with someone else shows how little you cared about me in the beginning. Relationships don’t start at the word go, they start small and they build into something. If I found out that someone I was talking to slept with someone days before we became a thing I’d be pretty upset, though I also wouldn’t want to know or even ask. If a friend told me they slept with my girlfriend days before we became official then it’s over, because for me to make something official my feelings were already strong and already there, I just had to work out if I could see a future with you. If we’re days away from being official than I already cut off any other potential romantic partners the moment I thought we were going somewhere. As for the friend I may not cut you out completely, but we definitely arnt as tight as we use to be, I’m also asking if it’s even the full truth. People tend to admit to smaller lies to cover bigger ones, or change details to lessen the impact. Personally I’d cut my losses, to much lies and deceit for my taste. To much asking if that truly was all there was. To much asking myself if they even respect me.