my friend is stealing my crush!?

[anon]

I told my 'friend' who used to go to my school but left that i thought a guy was hot there and that i kind of liked him,she didn't remember him at the start but then she added him on facebook.She told me they had been speaking and that he is so h**ny trying to rub it in my face that he speaks to her,I didn't believe that she actually had spoke to him untill i actually saw that they were friends on facebook,I really like this guy by the way.So yesterday i persuaded her to let me go on her facebook to talk to someone and pretend its her talking and I went through her messages to see if she had spoken to him,i know violation of her privacy right?She had been talking to loads of boys in a sexual way,and i saw his name come up,there were many dirty messages starting from when i told her i like him to only last week she had even sent him pictures of things!I am literally so hurt with why she would do this to me they were talking about meeting up and everything,i'm embarrassed and disgusted and don't know what to do because i don't want her to know i went through her messages but i'm so upset i was in floods of tears.. any advice?