It's a girl man. I would never let a long friendship come between a friend and me. There are other fish in the sea, and the way I see it, is this girl isn't really too interested in having a intimate relationship with you, so why let yourself live in heartbreak for this girl.

Just stop talking to her all together. Get her out of your system completly. If she's around school or whatever, ignore her, if you're at a party, ignore her. She is playing mind games with you and is being a little tease. I wouldn't waste 2 more seconds on this ditzy bitch.

Go be buddies with your rowdy brother again. There are millions of girls in this world, but there can only be one true friend. Go after someone that will treat you right, not get sloppy drunk and lick the first mouth she sees.