Iam in this very situation at the moment. I am the less experienced one. We ended up going farther than I ever had one night and I just recently freaked out and said I didnt want to do anything else. Now I am slowly getting back into seeing him lol He is very understanding, much like yourself.

Perhaps the fear of the unfamiliar is what brings it all home. I was ok doing things at first but then I felt weird after doing so and was all nevous about how inexperienced I am and how it probably wasnt good to him, I made an idiot out of myself etc etc

Maybe he is just afraid of being seen a immature for not knowing everything?