This just happened to me last week on a roadtrip I took with a couple of friends of mine, and I was so.. shocked, really would be the best word to describe it, that I just felt I needed some pro advice on the event.

Quick run down about myself, I'm 24, this is my first time looking up advice on any attraction related issue since I've generally always been the one to give it. And I have the reputation for being that guy who women go after, so I gotta be doing somethin right and this chick just destroyed me to say the least haha.

And now to the problem..

For starters, she's my best friends sister. So she knows what I'm known for, has seen me I guess "in action" a few times before, I only really met her about a year ago because none of us were exactly living near our home towns due to school.

She shows up with one female friend, and 5 male friends at our apartment, and we're all just basically chillin having fun etc, by the end of the first night I had her friend good and ready to go and i closed in every way possible.

Our last night of partying (after 4 nights, needless to say i paid little to no attention to my buddys sis for most of those nights). She starts coming on to me hard, my buddy (her brother) is passed out from the 20 or so shots he gulped down, and here I have his sister grinding me to watever songs they're throwing on.

She asks me for some gum (after asking me for a good 20 mins about a random girl I have a thing with, and if she was better than her).
Now out of respect for my buddy, I had no intentions of trying anything or doing anything, but this chick just basically pried it out of me.
Runs her hands all over me, asks for gum again, so i kinda bite down lightly on it and say, alrite but you're gonna have to come get it.
She does. We keep dancing, and she just starts telling me about how (insert watever complement here, she really threw them all, sexy, hot, irresistible etc etc etc) i am.
Then pours me 2 shots, and says "you're not drunk enough to do what you're conscience wont let you"

At this point i basically said, fuck it, took the shots, kept dancing, she throws herself on me drags me to a dark room, grabs me all over, pulls me in close and right when i go in for a kiss she says "oh.. you know i cant, you're my brothers best friend and my girlfriend likes you, next time maybe?" turns on the lights tells me shes tired and thanks me for watever and promises she wont tell my buddy that i tried that on her
at which point i just laughed, "but.. but you.. wow! you win, well played!" laughed again, and walked out and kept partying.

Is there something i missed or was she seriously just on a mission to fuck with me?
worse thing is, I cant stop thinking about that now, and her in particular.
Is this something thats happened to any of you? how can you tell if the girl just really is on that "oh im gonna fuck with him" mission? and did she do that just so i'd want her? cuz its definitely working, how do u go about getting a girl who does something like that?

Sorry about the long post, I had to get it off my chest haha.