Read your question. Overthinking? Wow - yes you are....and multiply it by 100. It was NOTHING. You did what youngsters always do. Party, booze, everyone drinks too much and gets flirty and you happened to get pounced on by a drunken girl. You didn't have to fancy her or anything. She was a stranger. She liked the look of you and threw herself at you and kissed you. That's all. You weren't interested so ditched her as soon as you could. The condom remarks etc are from your mates and if you look as though the remarks have hit home, they will continue to rag you about it just to get a reaction. Therefore, just smile and pull a face and shake your head. That shows you've accepted this sort of remark as the joke it is - but you aren't biting. They'll give up when you don't react - as will the girl.....eventually. The girl. She still likes the look of you now she's sobered up and wants to be friends on FB. She could be the type who just wants to collect as many so-called 'friends' as possible and her request to you is just one among many. Just don't accept the request. You don't HAVE to. No need to block her or anything - just don't get involved online with her in any way. Go to the gym as usual. Act like you've forgotten the party entirely. OK she'll be there and if she mentions the party or the kiss, act as if you don't remember her, it or anything. You could say, 'I was so out of it I can't remember anything at all about it after 8pm and the first few drinks'. If she mentions she's requested you as a friend on FB say 'Oh have you?' and then beat a hasty retreat back to the treadmill. If you don't engage with her too much, she will also get bored and seek other people to annoy.