<human>: I think a little background might be necessary for this one: 

So this new girl moved in at the beginning of this school year, my junior year in high school. My friend and I both found her very attractive, and as I had a thing going with a different girl at the time, he went for her and they started dating. I became really good friends with her in the mean time. So eventually after 3 months or so they broke up, my friend dumped her at a party and made out with some other girl the same night (dick move). 

After this, she expressed a lot of interest towards me, but as she is close friends with the girl I used to be with, nothing could really happen. So eventually this guy who she dated comes back and says he wants to get back together, managing to get her with at a party and playing on her still hurt feelings (Probably important to mention she has a lot of issues: self harming etc). He does this several more times, claiming he still likes her but telling me and all our friends he just wants to get some. So then spring break rolls around and this guy is on a trip for the first week, leaving a week of hangouts / parties that he wasn't at. 

I was talking to my friend (the girl) at one of these hangouts and (I have no idea how - thanks alcohol) we ended up hooking up, and hanging out the next few days. Over this time I really fell for her and I don't know how she feels, and I'm worried the second my friend gets back she will go right back to getting with him. Her friend whom I dated previously doesn't seem to mind us together but I can't really be sure. She is on a trip but when she's back, theres a big party which her, her ex and myself are all invited to. I'm not sure how to go about solving this one. 

So yeah, sorry for a bit of a read, any advice wold be appreciated.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: hooked up with friend who happens to be the ex of other friend who ha been treating her really badly post break up, started to like her