ADVICE IN NEED!!!

ok please here me out...

I swear to go, girls can be soo damn pissy! Ok here the story.
Spring Break 2005. Me and some friends meet up with guys, hang out till 2:30, then go back to our own rooms. One of the girls lost her room key, so stayed the night at my room. One of the girls told me to make sure that the friend that was staying the night in my room, didnt leave becuase she was drunk and all, i said i would keep an eye on her and that no one was leaving the room. Later on that night:It was her last night, and we couldnt get to sleep. So we end up calling the boys( which where seniors) and went to their rooms, and ya stuff happened there. We didnt tell the other two friends, becuase we thought they would be mad at us for either not listing to them, or not inviting. I'm not to good at keeping a secret about my self, and the guilt just built up, so i told her. She got REALLY upset and totaly went off on me saying that what we did was stupid, and we should have listened to her in the first place. I just dont understand why the hell she cares so much, and why shes taking this whole situation so damn personal!!! She now is even more pissed and is talking about how she doesnt believe us, and thinks we made the whole thing up, and that i'm a backstabber, and not a true friend... ahhhhh
Please give advicee!!

Please people, post

You know what you did, you know what happened. She doesnt need to believe you. As you grow up you'll begin to discover that you are the only one responsible for your actions and that for the most part they only hugely affect YOU. You know if you did something stupid, if you lied, if you put yourself in danger, etc. and YOU have to live with that, not her, so fuck whatever she thinks. You dont owe her an explination.

unless this chick was your chaperone or she wanted one of those guys then she really doesn't have a reason to be mad. maybe she is just jealous cause she missed out on the fun. u never know- us girls can be weird about stuff. lol

that doesn't make u a backstabber or a bad friend. at least not in my eyes.

Its pretty stupid, i guess i know the truth, shes wrong. I just dont want her to go around saying that i lied about this and that...