My boyfriend is not to keen about oral?!? How can I change this?

I love giving and receiving oral but my boyfriend of 7months is not into it. I've got him to do it a couple of times but he's doesn't really try and I feel like I'm being pushy :/. I just want it to be natural. I perform oralsex on him but I have like set a rule bc he thought it was fine for me to do it but not for him to do it, so if I do it to him he has to do it to me? Is that fair??.. Him not wanting to perform oral on me makes me feel self conscious how can I change this?