Dawning on what was happening you say "I wish my cock was a dog cock."
Then like magic it shifted from a pink tipped human dick into a full fledged red rocket, with a sheath and knot to boot.
He stared at his new footlong dog cock with amazement as he gingerly placed his hands on it to see how it feels. Incredibly it felt almost twice as sensitive as he was unable to hold back the lustful urge to jack off with his new toy, not even noticing as the butt plug started vibrating within his tight asshole, providing even more stimulation as his hands like lightning stroked his red sword to the max.
The sixteen year old couldn't even begin to fathom the intense pleasure he felt with his cock as he later there groaning heavily, his mind completely shadowed by lust.
Then feeling the pressure in his hot dick start to build up he makes another wish "I wish I won't orgasm until I chose so." He barely manages to stutter out with grit teeth.
With that wish he unwittingly traps himself into a nearly never ending cycle of pleasure and desire as no matter how intense the pressure and how fast he jacked off he couldn't orgasm driving him insane with pleasure as the buttplug continued to vibrate deep in his ass.
Finally he couldn't take the hot pleasure anymore and choose to orgasm, instantly thrown back against the wall as a literal spray of dog juice poured out of his thick cock everywhere, staining evething in the immediate facility. He couldn't help but let out a loud roar of pure overwhelming pleasure as his mind is flooded with pure lust, him obviously experiencing the best orgasm of his life so far. Even the buttplug seemed to have its own climax as it's owner's heart rate started to slowdown as he calmed from his intense experience.
Panting, the teen falls onto the ground, sitting in a pool of his own semen as he goes over what just happened.