Well .. I know i I was is your position .. I would definitely talk to him. The more you talk about the subject, the more comfortable he will feel doing it. The odd time he does go down on you.. Do you let him know he's doing a good job? If not start telling him he's doing great. Or talk to him and give him pointers. I love it when my girlfriend gives me pointers on pleasing her more. After all that is what it's all about. Where her spots are, what turns her on, etc. He might not feel confident enough to go down on you. Or scared he will screw up. Has he had previous sexual partners? If so, talk to them .. see if he was the same with them. HOpe this helps .. Im new to these forums today, so feel free to ask me othr questions.
Jabe