Oral sex

I know it's probably a guy thing but I give my boyfriend head all the time and he sometimes does it in return but doesn't enjoy it, I asked him why he doesn't do it often and he says I don't ask ... Well I don't have to ask, it should be mutual right? I think he's just really lazy on pleasing me... Because when he's drunk he doesn't have a problem giving me head at all. How do I get to give me head more without bein drunk ?