What does it mean when your partner has with you for hours?

and every time you do it with him you have to tell him to after 10 minutes. Even though I tell him that long hours is a turn off, he don't listen. I was reading in a column where the woman had this problem and the therapist told her that the bloke isn't even thinking of her and his mind is somewhere else. It's put me off with him and iv even split from him because of it. I warned him that I would find some one else but the other bloke did the same thing. Why do men think they have to prove their manhood by spending hours having . It's disturbing. what is the average time for a man to perform. I thought and would be happy with 10 minutes