Why does my dad do this?

I’ve been dating like really nice guy and from the beginning, my dad hasn’t been the biggest fan of him because he has a 4 year old son. (I am 26 my bf is 29) he always makes comments about other family’s who’s in the similar situations as me and my bf saying how “fucked yo it is” and so on. It’s really annoying and frustrating and makes me not to share any moments we have. My mom and literally whole family love him, he’s a great guy!!! My dad is the only one who has an issue!!! What do I do? Just ignore it??