Beautiful to wank off someone...feel the cock get rigid, feel the tension mount and then knoiw that you bvring him to the point of zero control, when he just has to release his sperm.......lovely sensation to know that you are in charge of his sperm production.
Reminds me of a time i had t9 g8ve a sperm count sample and was asked if i wanted a magaziene or needed help. I said what lind of help and he replied no oral but they are allowed to helpnwith their hands so i said i suppose thinking they were sending in a female nurse....instead he got his glove on and a bit of lube and gave me a handjob untill i came. He caught the cum in a cup and everything. Was a pleasant morning surprise.