Boyfriend doesnt cum

I've recently started dating someone who doesnt ejaculate during sex. He can last a few hours and he is very rough the whole time. He says he cums when he masturbates but I guess I cant say if that's true or not. He isnt on any medications. He is religious but says he thinks sex before marriage is okay as long as it's with someone special. I dont know why he isnt finishing I've read it could be to do with religion or performance anxiety. Has anyone had any experiences with this? I'm really confused about the whole thing and I do wonder if there is a problem and I do wonder about things like having kids in the future.