LONG STORY SHORT: (FULL STORY BELOW)

1.Girlfriend/friend begs you to come to her party.
2.She grinds and dances w/ your guy friends the whole night right in front of your face.
3.Pretends to be sorry later even though she knew what she was doing.
4.What do I do?

I have a friend/girlfriend (heavy flirting and stuff) I guess you could say we're still "talking" and she invited me to her birthday party. She made a big deal about how I better come and she's going to kill me if I don't and I'll make her cry if I didn't go blah blah blah. Anyway I went to the party and she spent the whole night grinding on all of my friends. And so I really didn't care at first because I thought she's just having fun, but she just kept on going from guy to guy the whole night and she spoke to me at least twice the whole night. So I left w/out saying goodbye and I got home and she calls me trying to be all sad (faking) and asking dumb questions like "why are u mad" and "did i do something". We've already done this kind of stuff before and I'm tired of always forgiving her. I need some help with should I just let her go do whatever or tell her I want for myself. She's already said she doesn't want me "talking" to other girls

This is a no brainer - if you want to put up with her behavior, then don't be surprised at anything that happens. Her behavior shows disrespect for you. Have you explained to her why you are upset at her "grinding" with your friends on the dance floor all night long? Do that nicely - no yelling at her, no swearing, just calmly have a discussion on how you felt when she was doing that and ask her not to do that again.

Now I have a feeling that she knew what she was doing. Girls are not that stupid! Neither are boys. You said you have been through this before with her. How much are you going to tolerate?

Have that talk with her - explain your feelings and how you want the friendship to go to a relationship. You both need to come to an understanding on what each of you wants from the other. What the expectations are and the willingness to make things work and the ability to compromise. It is never going to be all one way all the time. It is give and take - both sides.

If, after you have talked to her and you still do not get a feeling she "gets" you - then walk away. Let her go and do her thing. Take care of yourself.

Well, your friend doesn't seem like a friend to me.
It looks like she is just using you to get to your guy mates. I'm guessing they are good looking. But seriously, talk to her, tell her how you feel. She shouldn't be ignoring you if she was a true friend. But that's just me talking. For all I know, my advice sucks, but I'd like to think that it works.