I got drunk at a party and cheated on my boyfriend [FM]

I was at a party with a bunch of my friends and having a great time as you do at parties. We got there probably around 9 but I accidentally (lol) got too drunk so I left earlier than everyone else, probably around like 2:30 or 3:00. Not exactly sure honestly. Anyway, I always get super horny when I’m drunk so I wanted to go see my boyfriend. He had to work late so he wasn’t at the party, but he would have been off work by the time I was leaving. The party was at someone’s house just off campus so it wasn’t a far walk and I kind of stumbled my way there I guess. It’s kind of a blur.

The problem happened when I got to his dorm building but accidentally went to the wrong floor apparently. I go up to what I thought was his door, knocked once, and then just tried the door and it happened to be open so I just walked in. I’m sure you can see where this is going so cutting to the chase, I fucked this random guy who was certainly not my boyfriend while thinking it was.