You can't manage someone else's behavior. Nor can you change it for them. If she says rude or hurtful comments to you, be firm. Tell her her statement was hurtful.
Walk away from her.
Be honest...
if your girlfriend has a girlfriend, then she might not fully understand the concept of a faithful relationship, and is clearly Bi-Sexual. just let her know easily how you feel about that, and ask...
A simple answer .. When the time is right. Do not rush into a relationship because you want to have a girlfriend. You will find her when you are supposed to. "What's meant to be will find it's way."...