My parents had a messy divorce ten years ago and my father married the women he left my mother for. Now he wants to invite his wife's immediate family (parents and siblings) to my October 2014 wedding. He is contributing some money towards the wedding and he feels that this entitles his to include the people he wants to include. I'm not close to my stepmother's family and I don't want to make my mother feel more uncomfortable than she needs to. These extra people are not in my life and I'd rather not have them attend. Is this battle worth fighting? We also have an extremely large family and these extras are pushing the guest list to the max.