I'm jerking his bound cock to make him hard and ready then put a condom on his cock.
Applied a duct electric tape tight around the base of his cock and just under his cock's head.
It looks funny and his cock is very sensitive because of this tight tape.
Now I can have a lot of fun with his cock and bound balls, I'm doing a lot of things to him and he can't even cum.
Finally I took scissors and cut condom on the very top to uncover his cock's head, play with it and make him cum in a huge and very strong cumshot.