V: Vicarious
vi·car·i·ous: experienced or realized through imaginative or sympathetic participation in the experience of another
Your greatest pleasure comes from their satisfaction. Your pathetic little orgasms -- a trickle of cum, really -- from when you still thought of yourself as a real man could never compare to the profound pleasure of hearing mind-blowing sex at the other side of that bedroom door. Knowing that your hotwife/hothusband is getting all the sexual satisfaction they deserve, that their toes are curling when they are getting fucked by a real man, and that they're experiencing sexual ecstasy calling out another man's name gives you much deeper satisfaction than any orgasm ever did or could.
You have learned to experience pleasure and satisfaction vicariously. It is a psychological need to see your hothusband/hotwife satisfied that's much stronger than your own physical needs. You can fulfill that by allowing and encouraging them to find the sexual pleasure you could never give them with other men, but also by serving them in any other way they see fit.