Ñ I don’t like my stepson ADVICE ?!

Im a new mom, i had my son a month ago. My fiancé’s son is 5 .. I use to be ok with him back then because we barely saw him and I guess I hadn’t grasped him completely, he was always a little annoying but I could handle it. but Ever since we moved mid pregnancy, we got him a room at our house and during my pregnancy I started to develop ugly feelings towards him. I find him to be an attention seeker (I been know this since I met him) but now it’s starting to show MORE !!

My Fiancé can’t be with us because he calls for him, even though he doesn’t always give him what he wants, it still really bothers me.

He has seen his little baby brother like 3 times now and he ask stupid questions like “is that my brother?” “Why does he have hair”

He has never seen a real household before so he might be jealous? Can a five year old even be jealous!?