The perfect test of Rex II's obedience

Realizing that he only had enough money to pay for the pizza, Ryan felt ashamed. Ryan was raised to always tip well, but he had also been out of work for 3 weeks now. He had enough money to pay his rent due 4 days from now, but that was his last spare $25.

"You can keep the change dude, sorry I can't give you a real tip." Ryan says taking the boxes from the guy. "Wait a second." He says, after seeing the outline of a bulge in the man's khaki pants. "I think I have another way to tip you." Ryan looks down at his newly collared pet.

"Rex II, would you"