Mothers

I don`t want my mother to come to my wedding. My parents have been divorced since I was three. My mother hates my half sister, who is the maid of honor and her mother, who has always been kind to me and took care of me while I was younger. My mother is very insacure with herself and feel sthat nobody on that side of the family likes her. I jsut know that she is going to blow up and start a huge fight. She keeps fighting with me about it and hanging up on me. I don`t trust her to be able to control herself. She just hates people on that side of my family coming. But she is so irrational I don`t want to take the chance of her ruinning my time. What do I do?