It seems like if you're giving him oral he should be returning the favor. you do need to ask him, and ask him in a way that you expect him to eat you out. stop being so free with your giving him oral until he catches up since he's told you he's eaten out other girls. just quit doing it until he asks you what's wrong. when he does then tell him you need HIM to pleasure YOU now. make sure it does it at least a good as you do for him.
I dated a guy who never initiated giving oral too. I didn't feel comfortable asking him to eat me out so one day when we were making out on my bed and both completely naked I started kissing down his chest like I was going to give him head but with my body rotating so that my ass was eventually facing his face. He got the hint, pulled my legs over his head and started eating me out while I sucked him off. After that he never hesitated to go down on me. But if that doesn't work and he still doesn't get the hint, ask him to. If he says no, dump him. That's just rude.
I know of a guy who doesn't do that. He's tried it but doesn't like it. I personally think he may be gay, not because he hates performing oral on women but his mannerisms and stuff coupled with the fact that he doesn't eat out his woman of 6 years is just a little suspicious to me. Perhaps your guy isn't into giving girls oral but as someone else said, I would definitely ask. I can't imagine that he doesn't know you don't want it, but so long as you let it go down as it has been he isn't going to switch up the routine.
I'm not sure I could really get into someone who isn't into pleasing me sexually as much as I am into pleasing him. Anyway, start with talking about it and don't be afraid to speak up about what you would like. Don't give him head and see how he reacts to it, if he asks why, say I thought you didn't like it since you never seem to want to go there with me.
Tell that guy if he really wants you to suck his dick then he has to eat you out I am having the same problem a lot of guys ask me to suck their dick yet they wouldn't eat me out to save their lives. It's even worse when they said they would before but all of a sudden don't want to! Like, wtf? But yeah, if he wants head, and if he could give it to other girls, then he can give it to you. Otherwise, dump his sorry ass! Be like "sorry, but if I can't be your princess then you can't make me your ho." Tell him how it is before it gets any worse.
He might be afraid that he won't meet your sexual needs. Ask him directly. " Why do you avoid eating me out?". He might not be comfortable even though he may have had oral sex with other girls. Some guys say that they have either had sex or given oral sex to other girls as a front but they never have.
tell him he is making you feel self-conscious, ask if there is any reason why he isn't doing it. it's possible you have bad hygiene, or that "eating out other girls" means he did it once and hated it, he might just not like doing it.