Why isn't he going down on me?

Telling your partner what you want can be incredibly hot. If you say it the right way it's the "talk dirty to me" part of foreplay.

If he's not getting any of your hints (like sitting on his face) then just ask him.

If he seems reluctant say "I'll show you what to do" (hawt) and guide him through it (super hawt).

Even then, some guys just won't do it. So you'll have to accept that or move on.

You can tell him or guide hm as you make out and if he doesn't then he may not want to or know how, you may either have to show him and let him know it is what you desire and he may learn to like it

Some guys won't and don't ever, it's not their thing and sometimes it's better not to , sex is suppose to be satisfying if they can't it won't be as good and you will be frustrated

Don't force it or make him

Maybe it's just not his thing. I have ran in to girls that do not like to give oral and some who don't like to receive. Everyone has stuff they like and don't like.

Have you tried asking him? Maybe he is afraid to because he lacks experience in that department and doesn't want to look silly. If that's the case make sure you are patient and guide him through it. you may turn him into a oral animal!!

Tell him to do it. You gotta tell a man what you want. And honestly I wouldn't give head without receiving head... So stop going down on him and if he asks why then tell him you want some tongue action down there. lol