You know this sounds like that movie....what was the name.....Chasing Amy, right?
/smirk
Ahhhhh, Conversion. I don't know too many gay folk, but my understanding is flipping teams only works if they switch hit already.
I had pretty strong feelings for a lesbian once. She was pretty honest and open about....well just about anything, which is a trait I tend to admire. She assured me that she'd been through this before (my infatuation) and preceeded to pre-emptively shoot down any flipping and threesomes. She assured me that with time, I'd get over it and she was absolutely right. She turned out to be one of my best friends.
I don't know if that helps, but chances are if you're flaking yourself out she's on to you. Sounds like you're pretty comfortable with her, so I would suggest broaching the subject. Chances are she's already thought it out for you.