Mike shuddered as he shot out another thick white splatter of equine cum on the straw bedding. The multiple orgasms were leaving him dazed and confused, but the intense pleasure of the two boys' attention was like nothing he'd ever felt before. But where was it all coming from? The bedding under him was almost hidden by the transluscent white mass of sperm he'd already released, but he could feel his testicles swelling out full and taut again as Liam rubbed them.
The other boy, Aaron, had climbed up on Mike's back and was using the brush to pull out tangles in Mike's hair, grooming from the center of his forehead, along the middle of his skull, and down his neck. The long, slow strokes were hypnotic, dulling Mike's curiosity and making it easier to just accept this wonderful treatment.
Pressure built yet again, and Mike let loose another immense gush of spunk. The ejactulation lasted incredibly long, two jets, three, four. This one left him panting and lathered in sweat. He gasped out "I... don't know... if I can keep this up."
Liam laughed. "Oh, just getting you back to training age is good for 500 pounds. Not to mention the rest of your imperfections."
"Five.. hundred... POUNDS?" Mike blinked and shook his head, trying to focus his thoughts. "What do you mean.. back.. to training age?"
Liam continued rubbing the huge ballsack between Mike's hind legs, but replied "You wanna be perfect, right? Well, to get you properly trained up, you need to be no more than 3 years old, but two is even better."
"Two!?" Mike twisted his head around to stare at the stableboy. He felt really odd, but between the pleasure and confusion he couldn't pinpoint why. "I'd be a baby!"
Aaron was the one who answered. "Nah, you're thinking of humans. A two-year-old Clydesdale is like a young human teenager. Just ready to start physical training."
Mike struggled to work out what was wrong with that, but another intense orgasm rocked his body and he gave a strangled whinny of pleasure.
Whinny. That was finally enough for him to break out of the daze. his body felt wierd, not the horse parts, but his upper body. The human parts. It took effort to reach up and feel his face - and both the spindly child's arms and the discovery of a protruding snout drove home the fact that there wasn't much human left.
"Wha.. " Mike had to work to speak, his jaw not quite working right. "Wha' are you doin' to me?"
Liam grinned and slapped Mike's rump. "Making you perfect!"
"Yeah!" Aaron ran the brush down the middle of Mike's neck and back, brushing out the long mane. "A perfect Clydesdale stallion!"