My boyfriend has problems, please help.?

I am with a guy that I really love. We are polygamists, and we have about once a week (sadly). He just does not like to have a lot of . He is afraid that will get boring. But latly every time we have , he lose's his . Right in the middle of it, and we have to stimulate it back up. No, he is not gay, he is . And he swears it is not because of me, and I belive him. We are very honest with each other. So why is this always happening? We are living together and it kinda makes me upset. I know he is too. I just dont know how to make him stay hard. And yes I do give B.Js and such. Just.....help...any suggestions?