He knows that his pathetic little dick will never satisfy his wife. But he loves her and so he encourages her to fuck other men, preferably black men with big cocks. And she loves him and so she encourages him to watch and jerk off and cum as she gets fucked. It's a perfect marriage.
A good husband. He knows his tiny little cock can't satisfy his wife, so he lets her have something bigger and better. He watches and jerks off and can only squirt a few little drops of cum onto the floor.
I as a cuck that loves sharing his beautiful wife and seeing another man making love to her, I completely understand what is going on. I usually cum very hard, often twice, before my wife and her bull get to work, simply seeing them enjoying each other makes me flying