My fiance's younger brother has been dating a girl for a little over a year now. I was not a fan of her from the beginning, but I've tried to be friendly whenever we saw them. Nobody in the family is really a huge fan of her...she comes across self-entitled, and says things that can be offensive. She also moved into his house 2 weeks after first dating, and had his house decorated with her monogram a day later. My fiance's family is more on the traditional side, and didn't really approve.
She acted weirdly over-excited when we first got engaged. She insisted she had been waiting "forever" for this to happen (I had only seen her a handful of times prior), and she shared it all over her Facebook. The next time we saw them, she gave me an engagement gift (a Future Mrs. .... shirt). I thanked her for it numerous times, then went back to the reality of work and wedding planning.
Two days after receiving the shirt, I got a text message from her asking whether I really liked the shirt, and if not she offered to take it back for herself to wear one day. I was speechless! Unfortunately, instead of thinking about it, I answered quickly (I didn't know what to say!) and made a bad joke about them only dating for 1 year. I made it clear it was a joke, and even followed up thanking her again for the shirt and saying I was happy that they were so happy.
Well, she now refuses to speak with me or have anything to do with me. We saw them at another family event, and she walked out of her way to avoid seeing us. When I tried to start a conversation, she wouldn't look at me or talk to me directly. It turns out she felt I didn't show enough appreciation for the gift, so she offered to take it back, and my response made her feel I wasn't taking her seriously as a girlfriend. She also ignored everyone else in his family, and sat there with a "I dare you to talk to me" look on her face the whole time.
I don't know how to handle this...it's been the only thing my fiance and I have fought about during wedding planning. I do not want her there, but obviously can't not invite my fiance's brothers' girlfriend. I'm hoping she'll gracefully bow out, but that doesn't seem to be her style. I want my fiance to back me up and confront his brother about it, but he doesn't want to hurt their relationship. His brother is already not talking to their other brother because of something he said about the girlfriend.
How do I handle a plus one that I don't want there?
Thanks! Sorry, I know it was a long post!!