I'm nodding to all the comments here. Your BIL is just plain rude, period. You are a guest in his house and the guest should always be treated with respect and offered the choice of something before anyone else. Well, at least that's the way it was in my house growing up. Of course, there were 3 women and 1 man so poor Dad rarely got his way but if the guest wanted baseball then we all watched baseball. That's just good manners and everyone is right about the BIL setting a terrible example for the nephew.