Grabbing some of the special grooming supplies, Brian went to work on his friend. Mike was still basking in the glow of mating, and his mind was obviously a little thicker and slower. Mike's sensibilities had also changed, as the centaur made no comment when Brian slipped under his belly and began to stroke the still-slick horse cock. Brian was excited and aroused, leaning over the massive black shaft so that it rubbed against him. Despite just mounting the mare, Mike was still dribbling semen. Brian collected it in his hands and smeared it on his chest as a lubricant. Reach far back, he cupped the swollen testicles and felt them enlarge even more as the semen was replenished. Mike grunted, then said "Whatever you're doing down there, it feels good." His already deeper voice was getting gruffer, though the centaur did not give any sign he was aware of it.
Brian stepped out from under Mike and climbed up on his equine back. The Shire parts were done - just the upper portion of the centaur was still partly human. "Almost done. You'll be ready to mount the mare again soon."
Mike's face was protruding out into a partial snout, his eyes larger and set further apart over broad flaring nostrils. His skin was totally covered by black hair that was thickening into midnight horsehide. Brian held up a black brush that glowed softly in the dim light. "Ready to be a real Shire stallion?"