During the summer my best friend, jane, works at a summer program for 8 weeks. During that time her man, Jo, was out of the dorm as well, and ended up stay in her room. Ps, she's also my roommate. One night we started drinking with his best friend. Things start to get fuzzy near the end of the night. Next thing I know I'm under Jo, in her bed. By the morning I snuck my naked self out as fast as I could. Haven't told her about it, and I'm pretty sure he doesn't remember either. Should I tell her?

And yet you call each other "friends"...

Friends don't do that to their friends. Drunk or not.

I guarantee you it will be new roommate time when she finds out...

Sorry I agree with smoothy, that's horrible I hope she smacks you out. I would!

I would tell her by text after you have moved out.
Friends do not do that, and drinking is not an excuse.
I would tell her, since her boyfriend has few morals either.