Whenever you are not using your sub, leave him tied up and gagged, the tighter the better.
Subs love being held in inescapable bondage and they LOVE being gagged.
You don't even need fancy bondage gear, just shove your dirty panties into his mouth and use duct tape or a scarf to keep them in place.
(besides he should get used to the taste of your pussy right?
The best part is, you don't even have to stay with him. Just tie up up, gag and blindfold him, then leave until you feel like another orgasm!