I am getting married next year and we are sending save the date cards. My cousin had an emotional/sexting affair with my ex husband. It didnt last long and I blame him far more than her, but still, she never apologised. I have three cousins who I get on well with and want to invite. My Mum says that that will cause issues with her and her sisters, and make everything awkward and has asked I either invite all the cousins or none of them. I really don't want sex messaging cousin to come, I didnt like her much before this issue (she was always really condescending towards me) but I don't see why her poor behaviour should mean my other cousins don't come. But equally don't want to upset my Mum or cause problems. What to do.