I went to a bar with a few friends. We met up with another one of their groups of friends. Everyone was drunk. By some point most of my original group had left, but we ended up going back to one of the new group members' places to continue the party. (Just drinks, there were no drugs involved.) Back there, one of the new people (who had bought me a few drinks at the bar earlier; I didn't think much of it then, by this point we were both pretty drunk) really comes onto me, telling me how much he wants to go down on me. This surprised me as he was straight with a gf. (I have a bf, and we're NOT in an open relationship.) The thing is, if I were at a gay bar I would have had my guard up but these were all people who (I thought) were straight). That and a straight guy coming onto me is kind of a turn on. We went off, and he went down on me for a few seconds. Then he started freaking out, and I thought it would be a good idea to just leave. I feel terrible now. I won't be hanging out with these people again and I hope I don't run into that one, but in any case I don't have plans to initiate contact with him. I'm unsure on whether, and how, to tell my bf. I don't want to make him worry. In any case I'm definitely not going to go drinking without him again, I really don't want a situation like this to arise again.
In these situations there are always 2 options, which have different pros an cons You can either be honest and tell the truth, which would probably be better for you because you wouldnt be carrying it around. And it would give your partner the honesty that should be present in a relationship, but your partner might feel so betrayed that he will ultimately leave. On the other hand, if you are sure that it will never happen again, ever... you could spare him the emotional suffering and not tell him. Not telling him would be lying, and if he find out later he might feel that you have broken his trust which can have far worse consequences. My partner once cheated on me and in a sense I had hoped that he hadn't told me. The reason is that he told me half a year after it had happened and by then I felt that him telling me did more damage than good, because it hadn't meant anything to him at the time and he hadn't done it since I forgave him. I never fully trusted him again and it was always inthe back of min mind while I was with him. It is up to you what to you want to do, just remember to give him some space if you do decide to tell him. I would advice you to think the entire thing through before making a decision. Something must have caused you to do it in the first place, maybe an insecurity?
Authenticity, as far as I'm concerned, is always the answer. And telling a month or 6 months later has all the disadvantages of telling, and almost none of the advantages of not telling. So you need to do it soon, if you're going to do it. The previous poster has covered the reasons pro and con, and mostly I agree. The only place I disagree is I don't think it's OK not to tell to "save him the emotional suffering" because you're still being inauthentic and that's going to eat away at you and at the relationship. A healthy relationship requires vulnerability and that means being open. It also means he may be pissed, he may not trust you for a while, or he many even decide that he can't be in the relationship. But without the vulnerability, you're going to damage the relationship over the long term anyway. I also agree you need to look at why you allowed this to happen. Alcohol is basically just a license to do stuff you wouldn't do sober; if you gave in, then it's your fault, not the alcohol's fault, and you need to think about what put you in that position, and whether you can trust yourself with alcohol.
Tell him. You aren't very trustworthy, though. Mistakes happen, even to very good people, but this is one I just don't understand. Tell him. Be honest. Admit that it was a huge mistake and that you failed him, and his compromised your trust. Beg for his forgiveness and hope that he grants it to you. Then do everything in your power to restore his confidence and trust in you again by always acting in the best interests of the relationship. This is the honest and only way to recover to a truly healthy relationship.