I'm think I am not going to invite my fiance's mother to the wedding
It's a big event. Why don't you want her there?
She was rude to me before and I can't let her ruin my wedding.
It must be frustrating that she is rude to you. It's not cool to try to exclude your future mother-in-law from your wedding, though.
Whatever, no one cares. She's a bad person anyway.
Well, I guess it's your call since it's your wedding, but I still think it might be in your best interest to invite her because your fiance might think she is coming, so if you don't invite the mother-in-law, who knows what your fiance will do? Plus, the last thing you need is a wedding crasher, so it's best to invite her to keep an eye on her.