Since I have gotten engaged my FI mother has been asking what she should wear to the wedding. All along I said "whatever makes you comfortable and you feel beautiful in". She has then on multiple occasions asked me to tell my mother to wear a long dress in a pastel color because that is what she wanted to wear. I told her that I am not having any requirements for them because my priority is that everyone feels beautiful and comfortable and that I would not tell my mom that. She has asked me this like 100 times with me giving the same answer and getting very frustrated! Then she tells me that she decided since my mom wanted short and she wanted long they would compromise and wear a tea length. Again I told her to wear whatever she wanted but my mother would do the same. Now she decided that they will wear the same dress and we will all go shopping together to pick the dresses. My mom doesn't want to match her at all or even wear the same color. I am not sure what you are supposed to do or not but I figured everyone would just pick their own dress. I do not know how to tell her my mom doesn't want to match her without offending her and I do not want to shop with her anyways (she can be pretty mean to me at times which is a separate issue). I have told my FI and he thinks this is my department because its dresses and stuff. Any suggestions?