My moh has offered to throw us a couples shower this weekend. She asked me for a list of people we wanted to invite. So I gave her a list. She then asks me later if it's ok if her boyfriends invites four of his friends that are coming in from out of town. I do not know these people nor are they invited to the wedding. I told her I didn't think it was apprpriate for them to come since they are not invited to the wedding. She said that it's not that big of a deal and that I wouldn't even notice them. I feel uncomfortable having these people there without knowing them. In addition, my ffil has offered to pay for most of the food and fiancé and I think it's rude to make him pay for these strangers. Am I making too big a deal about this? What should I do?