I wanna know or have some type of idea.

Okay so me and my bae been fucking for a little of a month now but he doesn't go down he said I have to " earn it " but I go down on him and I was wondering how long will it take for him to go down? What do y'all think is he scared? Do he knows how to do it? Do he get grossed out when he goes down there? What really is the problem. Hell rather stick his thumb in my ass and kiss my ass than go down.