My fiance has two children; girl, 18 and boy 11. This is my first wedding and his second. He wants his son to be his best man and would really like for me to have his daughter has my MOH. The kids and I have a good relationship but I have a girlfriend and a sister-in-law I am much closer to and had envisioned asking one of them to be my MOH. He is offended at this. I am not crazy about an 11 year old being the best man since he cannot do anything the best man is supposed to do. I know this marriage will be creating a new family and I know I need to allow a place for the relationships he has with his kids at our wedding, so am I being unreasonable and selfish to only want them in the wedding party?