Controversial feelings towards gender

For some context; I have a 1.5 year old daughter (20 months) we also have two female cats one mine and one his so he’s kind of out number but we do live with his brother as well, my boyfriend isn’t the father of my child and came into her and i’s life when she was 3 months old and loves her like his own, that being said this is technically his first child and my second we’re due in July 2025 so it’ll be our daughter and this baby and granted we’re hoping for a boy but either way I just want a healthy baby but we were talking and he said he’d be really disappointed if their a girl and maybe I’m just over thinking but I’m just hoping he doesn’t have a dislike for her until he accepts it but we don’t even know yet so maybe I am overthinking lol, anyways thoughts? Opinions? Your own experiences? (we also won’t find out the gender until atleast christmas/new years so we don’t even know yet)