My own boy used to look forward to this position with horny dread. I took the Mr. S. locking cock-to-wrist restraints, and added a buttplug harness and a large plug. With the slave’s wrists locked in the cuffs, and the cockring locked tight around his package, I slid the connecting strap through the slits on the harness, and added an extra large plug. I’ll never forget the desperate, panicked sounds and cries he would make as the plug stretched him ever wider, until with a great cry, he’d feel his hole stretched past the widest point, and the plug slide firmly into place, his hole completely sealed. Then I’d lock the end of the strap in place, to the wrist cuffs, and there he was, utterly helpless and stuffed.
Then, I’d just slip around so I could sit with his head in my crotch, and let him suck me, or lick my balls as I jerked off all over his face and scalp. Those were some fun, pervy times!