<human>: Okay so, this is a pretty long story.

My boyfriend and I have been together about 10 months and it's definitely the best relationship I've ever been in and he's my best friend along with being my SO. 

We went to a friend's party the other night and I drank way too much (which unfortunately has been a common thread for me lately). I ended up kissing(or being kissed by moreso) a friend(F17) of mine.

As I've said I was incredibly drunk and of the actual incident I only remember being confused and trying to find my boyfriend. I told him immediately after it happened and naturally he left the party to get some time to think.

He left with a girl who we've both known for a long time. She dated an ex of mine and has been heartbroken ever since he left her. He only went with her because it was late at night and she was going to get food. After he returned I was upset with him and vice versa but we more or less reconciled and have talked about the situation quite a bit.

He says he forgives me for what happened but I'm not sure I can forgive myself. Along with this I'm highly intimidated by the girl he left the party with and despite any difficulties I've outlined to him about mistrusting her etc, she seems to always be around.

Could you distill the essence of the text into 1-3 sentences?
<bot>: I cheated on my SO while drunk at a party and it's causing a lot of strife between us. Also a girl who I do not trust seems to be around my SO a lot and it makes me uncomfortable.