He can’t ejaculate during vaginal sex

My boyfriend and I have been together for 7 months and everything is going great. The sex itself is good for both of us except of the fact that he almost never ejaculates while having vaginal sex. I have to perform hand jobs or oral to make him come. I don’t mind doing so and he says he doesn’t mind the fact he can’t ejaculate while having intercourse. He claims he still enjoys it and he wants to have sex pretty often. Nonetheless shouldn’t I worry? Is it my problem? Is it his problem? How can I make him come during vaginal sex?