"Okay, let's do this. I am on vacation. Might as well have some fun and try something new," said Carl confidently.
Radya squealed with glee. She jumped up and planted a large kiss on his lips. It felt strange having a muzzle pressed against his face, her large thick tongue filling his mouth. But it also felt good. He felt winded when she finally released him.
"Oh, you aren't going to regret this," said Radya with excitement as she sat back down on the bed. Before Carl had recovered his wits, she pulled his dick out of his boxers and held it tightly in her hand. Carl felt a sharp prick as she jabbed the needle in a large vein lining his dick.
"Hey! I didn't agree to that! Ow! Stop that right ...... oh... ooh," said Carl as his penis began to rapidly enlarge.
"Oh my, you are an eager boy, " said Radya as she continued to push the liquid from the plunger into the vein. She had to concentrate and continuously adjust her grip as his dick grew large in her hand.
Carl realized Radya had been right. It was the best erection he had ever had. He felt so big, his skin stretched impossibly tight as it continued to grow beyond what he thought was humanly possible. It was like those wet dreams he used to have when he was a kid. It looked like it was over a foot long and yet still kept growing! And it was so sensitive. Each time Radya adjusted her grip it sent shivers down his spine. He had never been so horny in all his life. It even felt like his balls were growing. He could feel them moving and churning down below. A little bit of precum began to dribble from the tip of his flattening tip.
"Not yet, hun, not yet, " said Radya as she grunted, pushing the last of the liquid out of the syringe. "There!"
Radya stood up off the bed to examine her handiwork.
"Now that is what I am talking about," she said as she stared at his cock with a mixture of pride and lustful anticipation.
Carl tried to look down to examine it, but he felt a little dizzy. For some reason he felt very lightheaded. If he had still been somewhat rational he would have realized that the blood flowing into his massive foot and half long dick had made him hypotensive. His cock looked strange, almost black. But then the whole room suddenly looked black as he started to pass out.
Radya quickly caught him before he could fall.
"Easy, easy there, stud, " she said as she gently sat him down on the bed. "Now let's get you more comfortable."
Radya worked quickly, removing his shirt, pants and all other clothes. Then she straddled him and assumed the reverse cowgirl position, sitting on his lap, her tail and ass facing him. She tried to guide his large organ into her wet pussy, teasing her labia open with her fingers. It was difficult work - his large dick was tight fit even for her large cunt, but with a little effort she was able to finally slide it in. Carl moaned as the tight walls of her slick vagina squeezed his sensitive throbbing erection.
"That's it, " Radya grunted. "Now I think we are getting the hang of it."
Carl lay back on the bed as Radya began to work her pelvis up and down, sliding his large shaft repeatedly inside her cunt. Carl was so overwhelmed with pleasure he didn't notice the black and white striped fur sprouting all across his body. Nor feel the muzzle slowly pushing out from his face. Or even his ears moving to the back of his head as they grew longer and assumed a triangular shape with a tip at the peak. His body began to slowly expand and grow larger, matching Radya's size. As his new larger heart pumped more blood through his body he felt more energy and sat up. Radya grabbed his hand in her own, placing his slowly merging digits onto her full breast.
"Mmmm... " she moaned breathlessly and she continued to rock his cock with her pelvis, "Don't stop. Keep going, hun..."
Carl was awash in pleasure and about to release his load when Radya suddenly stood up and changed positions. As his long shaft slowly slid out of her vagina, he was shocked at the size of it. And the shape. It was completely black and flat at the tip. It almost looked like ... well, like a horse cock!
He wanted to examine it more, but Radya gently pushed his chest with her hand, making him lay on his back on the bed. She wrapped her thick thighs around his legs and straddled him again, facing him this time in the cowgirl position. His curiosity was now forgotten as Radya began her gyrations in the new position.
"Ah... that's much better, " said Radya as she continued to buck and rock her hips.
Carl was so excited to it did not take long for him to release his load, just as Radya reached her own climax with a loud snort and whinny.
Radya slid off Carl and lay beside him on the bed, panting with satisfaction.
"What did I tell you? Best night of your life, huh?" asked Radya.
"Yeah, " said Carl exhausted, still trying to recover his wits.
"Well, that was fun. Real fun. But I gotta go, " said Radya as she sat up and began to get dressed.
Carl rubbed his chest, still enjoying the afterglow. Then he saw his hand - his hand covered in black and white fur with three digits ending in hard black nails. It hadn't been his imagination - he had changed into an anthropomorphic zebra like Radya!
He quickly stood up off the bed and tried to put on his clothes, now ridiculously too small for his large body.
"Wait! You can't go," said Carl with exasperation.
"Oh, you're sweet," said the fully clothed Radya. She gave him a quick peck on the cheek. "But I am afraid our time is up. I had fun though. Best I had in a very long time. Give room service a call later and maybe we can do it again. Remember to ask for Radya!"
"No, you don't understand. What about this?" he said dragging his hands up and down his new zebra body.
"Oh that, " she said as if it meant nothing. "It should wear off in a few hours. But do me a favor and don't let anyone see you until you change back. I can get into a lot of trouble if they know I gave some of that stuff to you."
Radya waved goodbye, then left the room.
Carl ripped the poorly fitting clothes off his body. Nothing of his would fit so it looked like he was going to have to be nude. And stuck in his hotel room for the next few hours, no less. Maybe there was something else he could do.
He didn't see a TV. But he still did have a large new toy to play with. Maybe he could spend the time pleasuring himself. Of course, there was always room service. Radya had warned him not to let anyone see him, but he was a paying guest. What could they do to him? The customer was always right. Maybe he would just walk around the hotel. He had seen plenty of other anthros walking around so he didn't think he would look too out of place. He could just fashion a towel or a sheet into some kind of toga. Or just walk sound nude, what did he care?
Carl plopped back down on the bed and considered his options.