Maybe he feels like your parents will see the obvious and not necessarily insignificant age gap. When I was 25, I would never date a 20 year old. Five years is a lot still at that age. I’m 35 now, and last year I dated a 32 year old guy and I still noticed it.

Think of it this way: no matter the chemistry between you two, you aren’t even allowed to legally drink yet because society deems you not fully developed.

I’m not saying this is what he’s thinking of, or even intuiting. It’s just one possiblity. It could just as likely be him wanting to be proper or traditional or respectful to your parents.

Like any relationship, just ask him 🤷‍♀️