Mike grabbed a brush with "Age +" written on its handle, and slowly began to brush the stableboy's bound body with it. The lad shuddered, as his naked body began to change. His frame getting larger, his limbs filling out, his already oversized cock and balls swelling to an even larger size. "Ohhh...." the boy groaned in dazed awe, as he felt himself become a man. Hair began to grow on his arms and legs and around his cock and balls, and a wisp of shadow adorned his jaw, which thickened has his face became that of a handsome young man.
When he looked like he was in his early twenties, Mike finally stopped. "Much better..." he purred in his deep centaur voice, admiring the man that the boy had become. The young man took deep breaths, his chest straining against the bonds that cut into his flesh. The ropes had been tied tightly to contain a thirteen year old, not a twenty-two year old man in his prime. He struggled against his bonds, but they only cut deeper into his perfect skin.
"Don't you worry... you won't have to be in there too much longer..." Mike promised, as he put the age brush away, and picked up...