Officer Den lay on top of Mike, his pulsing cock rubbing insistently against Mike's tiny opening. Mike moaned and officer Den shuddered, his body growing even larger as the sexual contact completed his transformation.
Officer Den's horse body grew even beefier until it resembled a Clydesdale's. Den's torso became extremely muscular and his chest became covered in a chestnut colored curly forest of hair that continued on his shoulders, down his arms and across his muscular back. Officer Den's face, already dark with five o'clock shadow grew a heavy medium length beard. His hair grew longer into a wild full chestnut mane and down the center of his spine he grew longer chestnut hair like a horses mane.
Den moaned and his voice was a rumbling deep base. He looked into Mike’s eyes and asked huskily, "Why have you done this to me?"
Mike said, "I didn't know it would happen. I thought I'd be a Centaur Mare forever."
"Well, if it felt this good, I can't understand why anyone would want to be human again." Officer Den said. "How would you like to be a Centaur Mare again?"
"I... I don't know...” Mike said.
"I'll be your stallion, you'll be well cared for, I promise you that." Officer Den said.
Mike wondered what happened to Den, he apparently wasn't the “fuck 'em and leave 'em” type anymore. The change had made him different. Becoming a Herd Master Stallion seemed to have brought out some fidelity in the transformed human. He smiled at Mike warmly and the look in his eyes was warm and caring.
"Take me inside of you again and you will be my mare, we will live as mates. I know a Minotaur Shaman who would marry us; he owes me a favor. Take me inside of you, my love." Officer Den said.
When Mike didn't respond, Den took it to mean Mike accepted and the stallion pushed into the tight hole.
Mike cried out in pain as he was impaled on the huge stallion's cock.
Officer Den truly tried to be gentle, but with such large equipment and such a small hole, it was almost impossible to not give his new mate pain.
It didn't last long. Officer Den's huge balls were ready to empty and in just a few minutes his thick Clydesdale seed filled and overfilled Mike's vagina.
Mike came a few moments later; Officer Den was still pumping pints of cum into the overflowing womb. He grunted and groaned, doing his best not to push too hard and injure his as yet un-transformed mate.
Mike began changing again, stretching, growing, Palomino blond horsehair beginning to cover her lower body. Her spine stretched and Officer Den looked on with lust as his mate began to re-grow forelegs from her stretching lower abdomen. He stroked her lovingly as she changed form; a golden blond tail pushing out from her plump rounding fur covered ass.
Fifteen minutes later Den's mate had finished her metamorphosis and looked upon her Centaur stallion in a new light.
Den said, as he clasped her head against his hairy chest, "You're the one I want, the one I've always wanted."
Within Mike's womb, a new life was conceived. A Centaur foal sired by a strong father and a swift and lithe mother had begun.
Den was happy and enticed Mike to have another round of sex: this time, Den could put all of his huge cock into his chosen mate.
Mike and Den spent the night in the shed, with the Dragon guarding the door.