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.