How do i get my older cousin to back off?

Hey! I'm 15 years old and my cousin's 19 years old. She spent most of her life in USA and unfortunately, she came back to haunt me. She's the flirty type who never gives up trying to hit on me, and well, she stayed over two nights ago and we had to sleep...

in da same room. I already got me a girlfriend and she has a boyfriend, she slept on the bed andi slept on da floor. When I woke up, I found her blowing in ma ear now what's up wid that?
Seriously I have no intentions whatsoever of cheatin on ma girlfriend so how should I break the news down to her. I tried EVERYTHING giving her the cold shoulder, treating her badly, making my point clear, but nothing works. Two days ago, she walked in on me in a towel!! Come on, seriously I need advice and fast! What should I do with my cousin?

First of all, she's your cousin and that should be enough. Second, she's an adult and you're a minor, which makes whatever she wants to do with you, illegal. Heck, just go to your parents and tell them your cousin is hitting on you, it's making you feel uncomfortable and you want her to stop. Your cousin must have big time problems if she is hitting on a younger relative.

Well, the thing is, if i try talking to my parents they will think that I'm the one who's hitting on her, not vice versa. The thing is, they think my cousin's the innocent type!
An other suggestions?

ouch...if u dont like iit , tell her and report it!

she's my cousin! I cant just report it! There's gotta be another way so she could get the message!

well...write her a letter xplaining how u feel!