You're the First Person He's Ever Slept with

Feelings aren't wrong or right. They simply are what they are. If I were you, I'd want to understand more about this reaction you're having. I understand that you are upset that he withheld this information for so long, but I have the impression that this isn't what bothers you most.

You seem truly upset to find out that he is without experience. Most people are upset when they find out that their partner had lots of previous partners and I wonder why this bothers you.

Instead of viewing his saving himself for you as a true honor and testimony to the strength of his feelings for you, you are discarding his gift and turning it into a negative rather than a positive! You said that you think his lack of sexual experience cheats you. In what way? Do you feel that he isn't a good enough lover as a result of the lack of experience? Or is there something deeper bothering you?

Dig deep and you may find that you are afraid that his lack of experience may bite you down the road. Maybe you're worried that sooner or later he will want to get that experience and you will end up being cheated on or dropped outright. You will need to soul search to key in to what the real issue is for you. When you uncover it, you can begin to resolve it.