This is a bit away but my bf wants us to go to his family in Michigan for Christmas. I have small children.?

I don't want to take them away from home during the holidays. They are not his children. They came from my first marriage. I just don't think it is fair to them, but I feel it is selfish of me to ask him to stay away from his family. I also feel like they will be disappointed on Christmas morning, because I can't afford to buy as many gifts for them as the other children in his family there will receive. My children are 6 and 9 and I think this would be heartbreaking for them. Any ideas? Suggestions to get out of it without hurting his feelings? He won't go without me.