No orgasm? Help?

Me and my boyfriend have been together for awhile. I've never had an orgasm while having sex, but it's not that the sex is bad, the sex is amazing, so I don't really care. But my boyfriend gets so upset that he can't make me cum and that he just wants to keep going for hours until I finally finish but I honestly hate that even more...
Can anybody else relate? What have you said to your S/O?