My fiance does not speak to his sister. His sister is bad news. She is drama, in trouble with the law, someone we do not trust or even feel SAFE around. We have made it clear that she is not invited to our wedding. Of course my fiances mom is not happy about this. There are 2 things my future MIL is paying for/putting on, the bridal shower and the rehersal dinner. While this is very nice of her, I have found the list of people invited to both and she has added on my fiances sister and child to both of them. She added the names onto the list I gave her. While I know she is paying, so there is not much I can do, I feel that this is rude. His sister shouldn't even be in town for the rehersal dinner if she is not invited to the wedding. We are worried that if she is in town, my future MIL will bring her to the wedding too. We did not want her to even know where the wedding is so she wouldn't show up and cause a scene. I would rather just pay for the rehersal myself and not have her there. What my MIL is doing is causing me a lot of anxiety and making the wedding process an upsetting one. Also, I'm afraid with all of this sister drama that my fiance will not follow through with the wedding. How should I proceed?