How to get her off my back and explain she's not that mature?

This girl and I used to be really close. Recently over the past year she's been getting more and more female doggier. The other day she made a comment on how her boobs were so big and that's why she's sexier then me. She keeps cussing at everything and being a whore. She's mean rude and nasty. If I like a Guy she just has to be caught in bed with him. I'm the kind if girl who would rather stay home and write then go drink and do drugs. Her recent crap is she told me that if I would think about getting breast implants maybe I could actually get a Guy to sleep with me. I told her I'm waiting until marriage and she said, "Are you trying to be a prude? Seriously suck it up and do someone." HOw do I get her to stop calling me immature and get her to leave my decisions alone. Am I really the immature one like she says?