I made the biggest mistake of my life a month ago, I slept with a pretty good friend who had a girlfriend. We've known each other for a few years now and we've always harmlessly flirted. I never thought anything would happen and nothing had ever indicated that it would escalate beyond flirtation. We both drank a ton and while that excuses nothing it definitely took harmless flirting way beyond that. The next day we both talked about things and we both feel awful and agreed nothing would ever happen again. Our friendship is different now and things are kinda awkward. He has been coming around a lot more lately because he is best friends with my roommate but I still find it odd that he's around way more now than he use to be. Lately every time he is around he drinks a lot to the point where he gets wasted. It's almost like he can't be around me without drinking and I don't know what to do. How do I fix things between us? I feel incredibly guilty for my actions and I don't want to lose a friend if there is anything I can do to fix it.