I have to get this off my chest. I have been with my finace almost 3 years. My oldest is 9 and his…

I have to get this off my chest. I have been with my finace almost 3 years. My oldest is 9 and his real dad ( not my fiance) has wanted nothing to do with him since birth. So my fiance is the only dad he really has known and my man treats him as his own, well he did. When I got pregnant I was worried he would treat my oldedt different because he has his own son now his own blood, he promised he would treat my oldest the same because thats his kid. Well thats not the case, now that the baby is here he completely forgets that my oldest is even around, never wants to do anything with him, yells at him for nothing. He is such a different person, I like that he loves his baby but why does my oldest have to be thrown to the side? I see his hurt, he thought he finally had a dad, my son has lost so much in his little life, first no dad, then my mom who was with him 24/7 (we lived with her and my step dad and she was his day a while I worked) passed in 2011 and my step dad left us, now my fiance is treating him as though he isnt around. Sorry it got long I just see my son so hurt