Todd looked at the woman, nothing more than the cock on the back end of a horse. He started to get aroused. He pointed the remote at the horse and shrunk her breasts, leaving nothing more than an equine cock and legs. He stripped down and walked up to the asshole of the horse, and penetrated it.
It felt amazing. Todd was in pure sexual bliss. He pressed a button on the remote to change the horse cock, removing the hair so cum didn't get caught. He removed the nose, leaving only the urethra-mouth and eyes, which were closed due to the pleasure of the situation.
Todd dropped the remote as he came, leaning onto the girl. She took a step back and stepped right on the remote, which was pointing at both of them. Todd yelled: "Shit!" and reached down to grab the remote, but got caught while bending down. He looked back up and realized his cock was stuck inside of the asshole of the horse. "What the hell?" he asked in disbelief as he pulled as hard as he could, but the pain made him stop. His cock was stuck inside the horse's asshole.
The girl had no idea what was going on, and couldn't look up from her position. She was on the edge of cumming, but something was stopping her from releasing. She took a step forward which caused Todd to fall forward onto the top of the horse-ass. His head and arms were in front of the ass, and he had a great view of the girl. He leaned back but was caught again, this time his whole chest was stuck to the back of the horse. He looked down past the woman, and saw his legs start to stick to the horse legs in front of them. The skin in between was sticking together, and soon his legs were the same as the horse's. He tried to move his legs but the horse's legs moved instead.
Through his shock he didn't realize that his cock was already gone, totally merged with the asshole of the horse. From his tailbone, a tail started to push itself out and he felt his asshole link up with the digestive tract of the horse. His spine soon followed, the extra vertebrae lengthening his body about below his arms, and he hung low with his hands touching the ground. His arms lengthened, and he pulled his head up to relieve the pressure on his spine. He felt a click and his head locked in a straight-looking position, and he felt the loss of touch in his hands. He felt a tingling sensation all over his body, and he couldn't see it but he knew that fur was growing from his body. He felt his body broadening, and his internal organs shifting to match. He bent over to look for the remote as his nose and mouth merged forwards, becoming a muzzle. His eyes shifted to the sides of his head, and he felt a crest grow on the back of his head. His transformation finalized as his ears grew out, and all traces of them ever being human disappeared.
Todd frantically searched for the remote, and saw it on the ground. He trotted over to it, and heard a sound that sounded like water hitting the floor. He looked down and saw horse cum all over the remote. He realized that he still had no feeling in his cock, which still had the girl inside due to the darting eyes. He ignored it and bent down to the remote, and looked for a familiar button. He carefully pressed it with his front hoof, and pressed a button that he remembered to say "reverse shift". He started blacking out, and he fell next to the remote.
Todd woke up, and he wondered why he couldn't see anything, he looked around and all he could see was darkness. He tried to reach out and remembered what happened to him the day before. He tried to move his legs but they were gone. He was hit with a very strong smell. He had never smelled it before but he knew it was a mare. He felt himself moving, but not to his own accord. He was hit with a blinding light, and saw a horse head licking his face. The head had a little bit of hair on it and... Wait. It's the hair of the girl he turned into a horsecock! He looked pass the horse head and saw the vagina of a mare in heat. He realized what happened to him. "Reverse shift" didn't reverse what happened, it reversed the roles of the shift. He felt his cock body and balls flare up due to the mare so close. His owner's head smiled. The girl realized exactly what happened, and was planning to punish Todd with pleasure. He looked forward as he was about to be penetrate the mare's vagina and...