Am I a bad person for feeling this way?

So my hubby and I have a 7 1/2 month old together and he has another son with another women. It never fails that every time we go to my in laws someone has to make a comment on how my son looks "so much like him" (his half brother) and I absolutely HATE them saying that. First of all he looks NOTHING like him. I can't stand my hubbys ex. She has done nothing but try to start trouble since my and my hubby got together. She think that just because she has his son she can get whatever she wants from whoever she wants it from. And I'm sorry but I don't want anyone comparing my son to a child that came out of her. Every time Wyatt makes a facial expression they are like "oh he looks just like him" and it just makes me angry! Can't my son have anything to himself? Does everything he does have to be compared to someone else? I always hated being compared to my sister, to the point I would cry over it and my son will not have to go through this. Maybe he's not like me and maybe he won't care but I'm sure sick of it! I just want them to be like "oh thats so cute" Instead of "Oh but he use to do the same thing Wyatt is". My hubby has talked to them about this and they pretty much don't care and haven't stopped. Am I a horrible person? I want you to be honest but please don't be a jerk or try to make it seem like "it's not that big of deal" because it is..