Story about a girl sold by her brother?

[jennicaxx]

I read it a couple years ago, it was a story about a guy who pimped out his sister to pay off his debts or something, and at the very end she's sold off.
I do remember that the story starts off with her in the car with one of her classmates or something that she thinks she's on a date with, but then it turns out that he paid her brother so that she'd blow him.
She didn't seem to put up much of a fight during the whole thing also.