So I've had some issues with my brother and SIL and need some advice. Basically since they got…

So I've had some issues with my brother and SIL and need some advice. Basically since they got engaged my brother has been treating me like I dont even matter anymore. Dont get me wrong, I understand his SO is going to come first but like to the point of not even being considerate of me. And I'm not sure if hes doing it on his own or if it's being dictated by her. So there was already some tension, then we went on a big family vacation together where they announced they are pregnant, great right? Well, yes, except when my brother and I were alone he said that my SIL "Hope's it's a girl because that's the only way dad (the grandpa) will love it more" than my baby. WHAT?! Who says that? I was in shock and processing it and didnt say anything only to realize how much it upset me later. So I told my mom, she confronted my brother and he denied it and said he doesnt even want to talk to me about it because he "doesnt want it to be a thing". That part seems sketchy like maybe my brother used my SIL as a scapegoat and doesnt want her to know? Or wasnt supposed to tell me what she said? I dont know. I'm not really sure what to do but this happened back in Oct and it's still bugging me. Someone who is supposed to love my son is wishing that he will be loved less and it both breaks my heart and infuriates me at the same time.