Dealing with internalized homophobia

So I have a situationship with this guy. We're friends foremost. Sex is on the table but we haven't done it yet. I really like him and it feels like there is a budding romance... BUT

This guy is Roman Catholic (huge turn off to me.) I'm atheist and grew up in a Christian cult. He's post doc researcher still believing in sky daddy... like, why? I get it, in Italy, Catholicism is the default. He doesn't bring it up often but he does make statements like "gay sex is dirty, there's nothing beautiful about it" and "STIs are punishment for having sex". Now, he has a very very dry sense of humor and it is often said with the premise of, he's joking. But I can tell he believes some of it.

He also feels broken and like he shouldn't be gay. The Catholic guilt gets him. I know it's not my responsibility, but I want to encourage him to think differently.

Have any of you dealt with this? What do you suggest?