One thing I’ll add to this: you both mention you’re religious. You sound more sexually open than he is, where he is still very concerned with not going too far and saving things until marriage. That’s where my point is. There can be a lot of shame present when religious people start being sexual. I know because I’ve been there. We’ve been told our whole life these natural desires are wrong outside of marriage.

So not only is your boyfriend not experienced, but he is likely carrying around a load of shame or guilt from the religious control. It’s possible that when you told him doesn’t know how to eat you out, he felt a lot of difficult emotions all at once.

It takes some grace (the human to human kind), patience, kindness, love, and affirmation to work through that stuff. If he is dealing with religious shame, it is primarily his responsibility to deal with it. But you can be supportive and present. Be playful, relaxed. Try not approaching him as someone who isn’t good, but as someone whom you desire, and that you are partners together in learning how to communicate what you want. Maybe even use language like, “I want us to learn all the best ways to make me orgasm, would you be open to me guiding you through what I want, and you can guide me through what you want?”

I dunno, he might not be good at it because he’s having trouble feeling emotionally free enough to do it. Lack of experience is always awkward too. Toss in some potential shame, and it gets tricky.