I know I've got just over a year to go until our big day but I've already had someone drop out of my wedding because of arguments. My SIL to be doesn't get on with MIL to be, & has told me today that she won't be coming to the wedding. It wouldn't have bothered me too much but over the last year we've become best friends, plus we were planning on asking her husband (my fiances brother) to be Best Man. She's said she won't change her mind, in the nicest way possible, even though I've told her I can ask the bridesmaids to keep them apart.
Bit gutted really, but don't know if or how I can persuade her to come.
Sorry if I sound like a winge bag, any advice on how I can solve this would be great 