First of all I don't have a problem with lesbians, it helps even up the unbalance with gay relationships and also the unbalance in straight interracial relationships.
Second, you admit she said she does not "love" you. Its just like a relationship with a man. He's married, he says he don't love you but you still let him screw you, you are not going to get him and you are being used. Same thing applies here in a gay relationship. Does it make sense to you? She is married, and you are not entitled to you her because she is a woman like you either.
Or, are you a man? Rules still apply, Sorry....
You could offer to participate in a 3-some with her and her husband. If you do you will have to submit to anything that may entertain them though including doing oral on him.