Frustrated...

Sierrah
So, hubby and I decided that we aren't going to find out the gender. We want to be surprised and we are very excited about our decision. Well, his parents (mainly his dad, who is over-bearing anyway) hate this idea. They are constantly asking us to change our minds and saying that they NEED to know so that they can prepare. They pretend like they're kidding every time, but it's getting so annoying. His dad even talks to other people about it and says stuff like, "I don't get why they're doing this...they need to just find out." What do I do?? We've been firm and said that we've made our decision already...