My father has offered to pay for my wedding, and when I asked who he wanted me to invite, he included my stepsisters (& their husbands/kids) and my stepmom's sisters. I am having a small wedding (< 50 ppl) centered on family and a few friends. I'm okay with inviting her daughters since I've met them several times, but I've only met one of her sisters maybe 2 times and I haven't met the other one at all. My dad says it's up to me, but I don't want to make my relationship with my stepmom any worse. Thoughts?