if you really like her, i think you should make her choose between you and the bf, if not in the end you are going to end up getting hurt.

if she chooses bf, then at least you know you position and still be friends.

anyway what she's doing is two-timing, if she could do this to current bf and you end up together, high chance she would do the same thing to you. dont think that because its 'you', she wont cheat. think about it.