Pisces have a crush on a cancer?

I've had a crush on a cancer female friend for the longest time. I wish i could tell her how i feel without the chance of ruining our 7 year long friendship. BUt sometimes i question if i am just infatuated with her looks as she is very beautiful. But I know there's more to her than looks. I've dreamed about her and i know im in love with her. Except her boyfriend is in the way.