My FILs have generously offered to host our rehearsal dinner at one of the nicest restaurants in the area. I was incredibly excited because it was really the first that they have shown a positive interest in the wedding. My FI just came home from visiting his brothers and has told me that his mother told his brother he is planning to turn our rehearsal dinner into a birthday party for my FI's stepfather. I am a little taken aback because she hasn't said anything about it to us when we've talked about it. I don't know how to deal with the news, and I am not sure if I should be upset or if I'm being selfish by feeling miffed because they are paying for it, and thus by that they can do whatever they want. Does anyone have advice about what I should do/how I should handle this?