Made me sit in the back

I’ve been dating this man for about 5 months and he’s great. He has two kids. His son is 9 and daughter is 12. He has full custody of his kids.

Anyways, we were going to go out to dinner and he made me sit in the back so his daughter can sit in the front. He said his daughter will always get the front seat. I get that it’s his daughter but it didn’t sit right with me. I don’t ever expect to come before her but I’ve always been raised that the children sit in the back and the adults sit in the front as a way of showing respect. I felt like a child sitting in the backseat so his 12 year old can sit in the front..

Just adding an edit: I don’t have anything against his kids at all but they are children and shouldn’t be treated as your partner. I’m going to end things with him because it seems he lets his daughter make all the decisions for the household and the other sibling. He checks with her before doing absolutely anything. just seems like an odd dynamic to me and I don’t want to be involved. Honestly feel like I’m having an affair or something with him at this point and the front seat thing was my tipping point.