Every time.

When we go to do foreplay he falls asleep or acts asleep and he doesn't get hard after we put the condom on. Why is this? He makes me feel so uncomfortable and small I'm not over weight or anything like that, I don't understand he says he loves me and wants to marry me one day but why is he like this sexually? We hardly ever go to do it anymore. He just tried it on and went straight to sleep after about 10 seconds. It's really hurting my feelings and he won't listen when I try to explain.