I slept with a close friend and I may have ruined several other friendships at the same time.
Why would you sleep with a close friend?
I have no idea, I was drunk at the time.
I can understand why you are concerned. It is not a good idea to sleep with your friends. It makes things complicated and uncomfortable.
It's not that big of a deal. I'm not saying I regret it, it was fun.
Even if it was fun, it's never a good idea to sleep with friends. It always leads to nasty feelings.