So I've been "dating" this girl from college for about 12 weeks now. We are not officially boyfriend/girlfriend yet, but close I feel like. We both are at our respected hometowns for the holidays.

Okay, so last night for New Years I went to a party with some high school friends, a little kickback. However, when it hit midnight this girl that I knew in high school leaned in and kissed me. We both were drunk but I knew this was not something I wanted. I got out of there after that (had a DD).

Now my question is, do I tell the girl I am dating or not tell her? This is serious and I'm kinda worried about what to do. I am trying to have a long term relationship with this girl.