Well, do what you feel is right in that regard, EE. But, I learned long ago not to step aside for the other guy. Either she wants you or she doesn't. Holding out for "maybe at some point in the future..." never works out in the end...for you or the girl.
Jealousy, anger, hurt, hatred. Pretty much in that order.
It's not a pretty thing to witness, and it's even worse to be involved.