LorienLlewellyn
There are a lot of reasons that a guy might not orgasm. Maybe he's not completely comfortable yet? Maybe he's always had a tough time orgasming? Maybe he gets off by getting his partner off? We don't know for sure.
So you're probably going to have to talk to him about it if you want to get to the bottom of it. You can talk about it without being rude, so don't worry about offending him. Just say something like, "I notice you don't orgasm most of the time. Is there anything I can do to change that?"
Agreed. You two can also make a point of learning and exploring sex together. Take him to the library and look at books about sex. If you're old enough, make a date of going to an adult store and looking at toys. Ask him how he feels about things like toys, foreplay, roleplaying, wearing costumes, using foodplay, and so on.
3nodding Communication is really important, so don't be shy. If he knows that you know more about sex than him, you can can play the role of "teacher" and open his eyes to things he might not know about or be aware of. Just make sure you make it fun.
And as Lorien said, there could be reasons why he doesn't orgasm. To add onto what she said, he could be nervous about sex still, or maybe he's overly tired or stressed at a given time. Again, you'd have to talk to him to find out what's going on.
Or, maybe he's not the type who orgasms a lot. I don't know how much men can be like women in this respect, but I know for myself, I don't ever really climax. But that's ok with me (thought not for my boyfriend, it drives him nuts lol). So maybe it's not that big of a thing for him, like with me. But you'd have to ask him.