This thread is all over the place but very, very, entertaining.
I think that you just need to tell her how you feel. If she says "I dont like you like that", then atleast you know, and could potentially still be friends, but you'd know to move on. If she says "I like you too", it is not directly breaking her up by saying malicious things about her current bf, it'd be her choice to leave him and go with you.
Truly the only way to pole vault yourself out of the friends zone (I like to think of it as a deep, dark hole) is to just say it.