Now, aside from the "friend rule" about not dating each others ex's, and her initially saying she wasn't interested in dating him and then going behind my back and doing it anyway, I'm faced with a problem.
When I asked her to be a bridesmaid in my wedding, she was single. She asked if she was going to be allowed to bring a date. I told her I didn't mind if she brought someone, because everyone else in my wedding party will have a date. That was months ago. Now I know the wedding is still a few months away, but I told her before they started dating (jokingly) that he wasn't going to be invited to the wedding. Because she "wasn't" interested, I thought it was just a laugh.
Now that they really are dating, she's mad that I am sticking to that. She said because I told her she could bring a date, I shouldn't take that back. It's not like this is some John Doe off the street. This is my EX! It's not even one I tried to stay friends with. When we were together, if we were in public, he'd pretend we were friends, and then he was cheating on me in OUR bed. I can't stand him.
I'm pissed at her for going behind my back about it and I'm pissed that she expects me to forgive him so easily. I hope it won't even be an issue by then, but what should I do. I really don't want to lose her as a friend, but it's mine and my fiance's day. My family and I would be extremely unhappy and uncomfortable with him there. What should I do?