BF can't cum with condom. help!

Hi, my boyfriend and I have great sex except that if he wears a condom he camt cum. He'll go for a long time and no result. He says it's great for him and he's never been able to cum while wearing one. We've tried without and he cums very easily then. I want my man to be able to finish but since I can't take birth control for medical reasons don't want to risk the pull out method. He's never pressured me into it but I want him to get pleasure out of it too. Also I feel insecure when he can't get off!