As Kyle hobbled off to the restroom, James was discretely watching him. James never considered himself gay, but after seeing Kyle's bulge in the changing room and now seeing his obvious erection, he just had to watch Kyle. Maybe he had something of a voyeur streak. Either way, he asked the teacher if he could wait for Kyle to finish so he could go right away. Once again, the teacher reluctantly agreed and off James raced.
As he found the outhouse, he caught sight of it as soon as Kyle was shutting the door. In a mental battle between common sense and his libido, common sense lost out to his dick. James snuck beside the outhouse and peeked through the vents in the sides. His jaw just about dropped to the ground when he saw what was inside. Kyle was stroking and rubbing what looked like a horse cock! It was absolutely massive, coming up to Kyle's chin as he sat down, 2 feet at least. James could only stare transfixed as Kyle hypnotically pleasured his equine looking dick. As the minutes ticked by, James noticed as Kyle's member began to grow a bit more; the head seemed to take on a trumpet shape and it stretched out an inch or two more. Then, without much warning, the huge horselength gave a powerful lurch as a large rope of ejaculate tore out of it.
James couldn't move fast enough though as a splash of chunky horse cum sprayed out through the grille of the vent, a few strands catching on his face. As soon as the horse cum touched him, he felt flushed and hot, even moreso than he had been watching the incredibly erotic scene unfold in front of him. His already erect member swelled with even more blood, pounding in tune with his heartbeat. James had no idea as to what was about to happen to him.
As he sat down behind the structure, he impulsively yanked his pants down, determined to take care of his raging erection. What he saw when he dropped his undies made him freeze in shock; His dick was slowly growing, already at about a foot in length and growing! His cock wasn't the only thing to change, either. His sack was now a black leathery color and texture that seemd to be spreading up the length of his member. His balls swelled in their home, growing past ping pong balls, golf balls, and tennis balls. Concurrently, his cock kept on growing and changing. As it grew, it's color shifted to a mottled pink and brown/black, the head flattening from a crowned knob to a flat, flared blunt tip.
As James stared at it, he couldn't stop what was about to happen. His arousal continued to grow and grow, his dick throbbing and pulsing in need. Before the change, he had never felt this sexed up about anything! Even the smallest touch would send him over a monumental orgasm he couldn't even imagine yet. He reached a hand up to touch it, feel it even. The moment he brushed his fingers over his newly formed medial ring, a deep fire began in his cock. He yanked his hand away, but it was too late; the point of no return had been crossed. His monster throbbed once, twice, three times, feeling a hot liquid travel up its length. At the fourth pulse, a geyser- nothing else could describe it- exploded from his horsey dick. James fell limp as his cock had its way with him, cumming out of control. After what felt like minutes of bliss, James comes enough to his senses to see Kyle standing over him.