SketchPad and BluePrint’s house was set atop of Mount Grandlin just outside of Ponyville down a path leading through the Everfree Forest. It was a peaceful spot just above the dangers of the forest itself and the path leading to it had been enchanted by unicorn magic to keep the creatures that roamed the dark wood at bay. The house on top of the mountain was a decent size for two ponies to live in. It was a large, bluish, rectangle structure, a broad tower shooting up from the center of the main structure's roof, making it even bigger.

There was a female unicorn waiting on the porch of their house today. She had a pink mane and glowing yellow fur all over her slender, nicely curved frame. She was a healthy young mare wearing a tight black shirt and cut shorts, and her hooves glossed and shined like jewelry. Her name was Mimie, a pony well known at one of the hangouts in town. She had followed the trail through the Everfree Forest, enchanted by unicorn magic to be safe from the rest of the mystical wood. As if that wasn’t enough of an impressive bit of magic, she had literally pressed her hand against a hidden magic glyph set upon the rock wall at the base of the mountain.

It was a seal that only shown itself to friends and welcomed acquaintances. The glyph had teleported her up at the very top of the mountain, giving her a wondrous view of the town below. She had visited this place before, but it had definitely been a difficult thing to get used to. Now she was standing on their porch, after walking up a nicely spread path. She had come all this way to hang out with SketchPad, enjoying the little downtime she had from working at the bar.

“SketchPad, it’s me, Mimie. Hurry up bud!” she called out knocking on the door

“Be right there!” a voice echoed from inside the house. A short moment later the door pushed open and a tall brown colored pony with a fluffy black mane glanced back at Mimie.

“Hey Sketch!” She said cheerfully putting a hoof through the doorway and stepping inside.

SketchPad smiled and welcomed her in, shutting the door back tight. They stood in the front living room, where a few comfortable pieces of furniture including beanbags, couches, and armchairs were set along the walls. It was a bluish kind of room just like the outside of the house. Most of the house itself were comprised of rooms filled with their own different shades of blue, complete with a different designs of blue wallpaper covering the walls of each section of the house. SketchPad walked over and sat at the center couch and Mimie joined him as they began to happily chat.

Further downward—even past the basement of the house itself was an iron staircase that led down to a large rounded metallic door. Behind the door, the sounds of pipes clanking together along with a low hissing sound could be heard. Beyond the metal door was BluePrint’s laboratory; it had literally been built inside of Mount Grandlin right underneath the house. It was a large place, not at all a bluish color like the rest of the house. The walls gave off a grayish green tone and a strange fog always seemed to come up off of the metal floors. Strange machines with clear tubes and wires protruding from them were all gather around different corners of the large lab area. The laboratory itself was enormous, and at first glance, it easily looked three to four times bigger than the house that it was underneath.

In the west section of the laboratory, there were large glass capsules set against the wall, along with shelves holding flasks and bottles of strange, glowing liquids. This was the part of the lab that BluePrint worked on potions and experimented with many unique chemicals that he had managed to gather around the Everfree Forest’s plant life. Counters were lined up along the wall that hadn’t already been occupied by the large capsules, and at one of them stood BluePrint. He was dark blue—one of the only bluish things in the lab itself and he had a long wavy black mane that spread down around his neck and shoulders. He wore a white lab coat, baggy grayish pants, and a lighter blue bandanna wrapped around his neck.

“Okay now—let’s see…”

BluePrint stood at the counter unblinking as he slowly tilted a small glass tube filled with green liquid over a flask full of a color changing, smoky substance.

“One, two—,’’ he chanted softly as the green liquid dripped carefully into the flask.

“And three—“

BOOM! A mini explosion flashed right in front of him, yellow-orange smoke shooting up into his face as he swished away the cloud of chemical dust with his hand.

“I’ve done it!” BluePrint’s yell echoed throughout the lab, although it was too far down into the mountain for SketchPad and Mimie to hear anything.

He leaned down over the counter and stared at the flask as the smoke cleared and an orange liquid appeared. BluePrint grinned wide and jumped up and down happily following it with a little jig. He had been working in the lab for three days straight with barely any rest, but finally he had finished.

“My gender transformation elixir—finally mixed to perfection,” he exclaimed as he jogged over to a chalkboard, running his hand over the complex equations already written all over it.

“As long as the mixture is correct, the potion should transform stallions into mares—and mare into stallions! A complete gender swapping formula—I’m going to have so much fun testing this out,” he squealed taking up the flask in both hands, holding it up on his fingertips, marveling over his creation.

A wide, sly grin began to form along his face as his eyes darted upward at the high ceiling. The newly mixed potion fizzed and popped in the flask, still a bit hot.

“I know just who to test it on first,” he said with a faint, sleep deprived, slightly terrifying chuckle.

BluePrint was talking about his roommate, lab partner, fellow traveler, and number one guinea pig—SketchPad…

Two levels up, inside of the house itself, SketchPad was with Mimie in the living room watching movies on their television. The metal door of the laboratory had slowly creaked open—and out hovered the orange potion. It was being controlled by BluePrint as he crept upstairs into the basement, and then up the stairs to the main level, his unicorn horn glowing faintly. The basement door led straight to the kitchen, which was very convenient for BluePrint. He peered around the corner and noticed no one in the kitchen. All he could hear was the movie finishing up on the television in the living room.

Quickly he maneuvered the potion toward the refrigerator as magic pulled the door open. A large open container of apple cider slid out and was quickly replace by the orange potion, sitting in a similar container. Within moments, the refrigerator door was shut and the cider was hidden. BluePrint grinned wide—but then slid down the stairs and rushed to his lab in a panic when he heard the two ponies coming into the kitchen. The movie had ended.

BluePrint slid over to his favorite desk and his horn glowed once again, causing a long keyboard to flip over into view. He pressed a large button at the top right of the board and the wall in front of him slid open as a large monitor appeared. It turned on and the image of SketchPad and Mimie popped up on the screen. BluePrint stayed quiet, a pen now in his hand and a journal on the desk before him. It was time to take notes—time to see if what he had managed to mix together was a success or not. His eyes glued to the screen right as SketchPad was pulling out the container, filled with his gender swapping potion.

“It’s nice to kick back and enjoy a movie sometimes. BluePrint and I haven’t been home for nearly three weeks. The last trip we took around Equestria took a lot out of us,” SketchPad explained to Mimie as he poured the orange liquid into two cups.

Mimie grinned.

“Well, you shouldn’t get used to it. No good in being a lazy couch potato for the rest of your life. You and BluePrint have a lot of fun together right?”

“Yeah but this week I thought I’d just enjoy my house for a week.”

SketchPad and Mimie laughed together and continued to talk standing next to the kitchen counter. BluePrint anxiously watched the screen silently chanting and looking right at the cups of potion.

“Drink it, drink it—drink it!”

“Mm, apple cider, it’s nice to drink something without alcohol in it for at least a little while,” Mimie said finally taking a decent gulp of her share of orange liquid.

SketchPad nodded in agreement and just as quickly downed a decent gulp of the still warm brew.

“Hmm, that’s weird; it’s definitely not as cold as I expected it to be—Ugh, and it doesn’t even taste like apple cider, what the hell?!”

BluePrint nearly let out a maniacal laugh, but held it back, too interested in what was to happen next. Although, to his disbelief—something completely different came from his new potion. SketchPad hadn’t changed—and neither had Mimie. SketchPad was already rinsing his mouth out with water from the sink. BluePrint huffed. What could he have done wrong? The potion hadn’t done anything. At least for a moment—that’s what he had assumed. But Mimie stood there completely still. SketchPad had already tried to apologize for handing her something that wasn’t apple cider, attempting to hand a cup of water to her, but something strange was happening.

Mimie began to slowly pant and gasp for breath. BluePrint began to look worried. Was Mimie sick? All of his chemicals were safe for consumption. He had even used his own magic to dilute any possible poisons from the ingredients he collected from the forest. Mimie leaned back against the counter and SketchPad stood next to her, his hand on her back—a worried expression now on his face.

“Whoa, are you okay? Dam make him give me an antidote for this right now!”

BluePrint screeched a bit in shock and immediately locked his lab door with magic. SketchPad was getting ready to come and get his "fail-safe" potion, an elixir that he used to restore anything influenced by his crazy concoctions back to normal. Because of BluePrint, SketchPad had been turned into a cat, a cow, a diamond dog, and even a baby version of himself. And he had told BluePrint off enough times until he had finally decided to concoct a reversal potion, which had surprisingly worked each time.

He would have given it to SketchPad if he had knocked on the door, even risking a smack across the head from an angry roommate—he had no choice or reason not to. But before SketchPad could make another move, Mimie’s voice faintly called out to him as she gripped the edge of the counter. SketchPad immediately went back to her side. BluePrint painted his face to the monitor again.

“Don’t worry Mimie, you’ll be fine. BluePrint's potions are completely nonlethal. Nothing harmful—just generic poison joke effects,” he snarled a bit still very irritated, reminding himself under his breath to whoop BluePrint's ass later.

Mimie shook her head and SketchPad stared beginning to look confused. Usually at this point the potion would have done its job and transformed the drinker instantly. SketchPad was even more confused when he realized that he was still his normal self. Then Mimie finally caught her breath, sweat dripping down her chin, her mouth wide open as she looked down.

“Something is—pushing—against my shorts. It’s too tight!” Mimie blurted out as the panting started up again, heavier this time.

“… Uhm… What?”

SketchPad’s eyes darted downward and went wide. Down in the laboratory, BluePrint’s eyes were just as wide as he wildly scribbled illegible chicken scratch into his experiment log.

“What in the—?” SketchPad couldn’t believe what he was seeing.

“Help me—it’s—so tight!” Mimie blurted out again.

“What do you want me to do?”

“Unclasp the button and unzip me!” Mimie yelled.

BluePrint nearly stopped writing as he gawked at the monitor. SketchPad hesitated for a few seconds, but finally he nodded his head, knelt down, took a big gulp, and then popped the button on her shorts, and dragged the zipper downward. Mimie let out a sigh of relief and soon SketchPad’s eyes were even wider than before. Something thick and fleshy had sprung out from her shorts and and flopped down over the bridge of his snout, right between his eyes.

“Holy shit—is that? That’s a—,” BluePrint stuttered loudly, breaking from his trance as his pen darted across the journal faster than he could think.

SketchPad fell backward and looked up. Mimie’s hands were pressed to her face, still leaning up against the counter. Her shorts were open—and what had managed to pop out from behind her striped panties—was a decently sized yellowish, fleshy horse cock.

“S-SketchPad? W-why do I have a dick!?” Mimie huffed and panted.

SketchPad stared in disbelief for the longest time until Mimie finally called out his name once again.

“Uh, hold on a minute I just remembered that I made BluePrint keep the "fail-safe" antidote right here in the kitchen—in this closet,” he said rushing toward a green colored closet door, swinging it open to find potions lining the shelves inside, all made by BluePrint. In bold lettering at the very top left, SketchPad saw a vial with the label that read: Fail-safe, Cure All Elixir. He grabbed it up and found himself having to help Mimie take a drink, holding the vial up to her lips. She gulped down the liquid and SketchPad sighed in relief—until he felt something hard poke him in the thigh. He looked back down and gasped. The Cure All Elixir hadn’t done its job. BluePrint’s hands slammed onto the desk.

“What! The "failsafe" doesn’t work!?” BluePrint bellowed out.
SketchPad felt himself getting close to panicking now as he looked at the vial of antidote in disbelief.

“…SketchPad.” Mimie’s faint voice caught the brown stallion’s attention again.

“Y-Yes?”

“It’s really hard—and I’m getting really dizzy,” Mimie said suddenly leaning against SketchPad, grinding her newly grown horse penis against his leg.

“Do something about it please,” she muttered out.

“B-b-but—B-b-but!” SketchPad stuttered frantically.

“I can’t do it myself,” she said faintly barely grasping his hand and dropping it right over her fleshy extension.

SketchPad’s fingers slowly and reluctantly curled around the fleshy girth hanging from between Mimie’s legs. He looked at her half shut eyes and nodded. He gripped her tight and she let out a loud moan. BluePrint’s face was flat against the monitor for a few seconds before he leaned back in his seat and stared blankly, the pen falling from his hand.

“I created a futa pony potion,” he coughed out, his journal full of chicken scratch that only he would be able to make out.

Mimie gripped SketchPad’s wrist lightly and started to tug it back and forth. SketchPad’s had slowly began to move on its own, gently stroking Mimie’s newly grown futa cock as she rested against the kitchen counter, softly moaning. His hand sped up, cupped around her, dragging up and down her length as he stared down at—he could believe what he was doing. Mimie grew harder in his grip as her moans become louder. She gritted her teeth and wrapped an arm around SketchPad’s neck, looking down at his large brown hand jerking off her yellow horse cock. Her legs shook a little; her knees rattled as she slowly began to buck her hips slowly sliding back and forth between SketchPad’s fingers.

It was sudden, but without hesitation, it was as if Mimie had regained her strength back as her arm pushed SketchPad down unexpectedly to his knees. The flat tip of her fleshy protrusion aimed right at his muzzle. She breathed in and out heavily, orange smoke seeping past her lips as she knocked over her cup of potion. SketchPad’s eyes darted up at Mimie, watching her lips move and curve up into a wide smile.

“Suck on it. Now!” she commanded.

“Wha—Mmmmph!!!!”

That was all SketchPad could say before a third of the thick yellow horse dick slipped past his lips and dragged across his taste buds. Mimie grunted and immediately a thick spurt of precum coated SketchPad’s tongue. His eyes couldn’t go any wider as he gulped, grasping Mimie’s legs as she began to slowly force more of her futa cock deeper into his mouth, a deviously horny grin on her face now.

“That’s it! Suck down every inch—nice and slow!” She said, her hips pushing closer against his face.

All BluePrint could do now was watch dumbfounded with a cocked eyebrow as the short yellow mare managed to slip the ring of her new horse cock past SketchPad’s lips. More than half of it was in his mouth now, the flared tip of her horse sized length resting deep in his throat. She managed a few more inches further, his snout just about to touch her panties, just before she managed the entire length, she pulled back outward, all the way, dragging her saliva coated member out of his mouth until only the tip rested on his tongue. Thick strands of drool hung from the bottom of the yellow cock and the brown stallion’s chin as Mimie stood there panting and giggling.

“Ready for more, SketchPad?” Mimie asked with a smirk as she placed a hand under his muzzle.

SketchPad’s mouth was wide open, his tongue dripping and hanging over his bottom lip. He was panting lightly, his eyes transfixed on the yellow flesh that had been deep inside of his mouth-- all but just a few inches of it. And from the look on his face as his gaze went up to meet the yellow mare's stare, she knew his answer. Whether it was unconsciously or not, he wanted the rest. Mimie smirked as she felt his large hands grip her legs, looking at the thick, yellow shaft hungrily. The brown stallion’s wet lips closed around and gently suckled on the tip of her fleshy extension. He was in a complete trance. Maybe it was the potion finally taking affect but now—SketchPad seemed to be under Mimie’s control, at the very least not putting up a fight. Mimie grinned and slowly began to push her hips forward again, feeding her fleshy hose right back into the stallion’s mouth.

“Good boy!” She huffed, within seconds burying her length down his throat again, all the way this time.

Mimie’s hips began to move on their own, gyrating at a slow pace as her horse cock dragged back and forth across SketchPad’s taste buds, throbbing against his throat muscles as they contracted tightly around her. Mimie shuddered in pure ecstasy as she thrust her pelvis against SketchPad’s face repeatedly, her fleshy mare-hood pulsing on his tongue and ramming against his throat hard with every hard buck. Surprisingly, SketchPad took every inch without gagging. He was too deep in his trance to pay attention to how much the small yellow mare was shoving against his windpipe. From the thick lump coming from SketchPad’s neck, BluePrint could easily tell from watching his monitor that Mimie wasn’t holding herself back. Her tongue hung past her lips as she held onto the back of the brown stallion’s head and continued to ravage his face-hole with her futanari dick.

“S-SketchPad—I-I can feel something coming up,” Mimie stammered as her fingers curled up and tangled in the stallion’s mane.

“I think—I’m going to—!”

Mimie knees buckled as she slammed backward against the counter and recoiled her hips forward. She had lost control of herself as she pulled SketchPad’s head as hard as she could against her groin, driving every single inch of her mare-hood past his lips. Mimie let out a loud echoing groan and BluePrint’s jaw hit his desk. SketchPad’s trance broke immediately. His eyes went white as he gulped down a hot mouthful of very thick goo, some streaming down his chin. Mimie was pumping hot ropes of cum right down his throat. Thick gobs of creamy spunk lined his esophagus as Mimie held his head in place, pumping more and more right into his stomach. By the fifth thick blast of gooey nectar, SketchPad had gone motionless. His eyes were half shut as Mimie finally pulled out more than halfway, letting another raspy groan escape her mouth as one final thick coating of horse cum spurted from the flared cock tip and filled the stallion’s mouth—SketchPad’s cheeks expanded and he swallowed down his final helping of yellow mare goo.

Mimie regained her senses as SketchPad leaned forward on all fours and coughed a few times. A final small cloud of orange mist seeped out of the yellow mare’s mouth as she looked down and realized that what she had been ramming down her friend’s throat had shrunken and disappeared. Mimie zipped and buttoned her shorts back up, locking eyes with SketchPad as he looked up at her, a look of disbelief plastered all over his face, leftover cum trailing down his chin and neck.

“That—definitely wasn’t apple cider,” said Mimie as she looked down at the spilled cup of yellow-orange liquid, still panting softly.

SketchPad wiped his chin clean and stood up, looking down at the orange liquid dripping onto the floor.

“I guess not,” he muttered faintly and awkwardly.

A few minutes later they were standing back at the front door. SketchPad held onto the doorknob, a blank expression on his face as Mimie stepped onto the porch and looked back at him. She gave the brown stallion a quick peck on the cheek and smiled. All SketchPad could accomplish was an emotionless gaze as he looked over at her smiling face. Mimie was grinning—her face was beaming.

“That was fun! I’m not sure how to feel about the whole ‘mare horse penis’ thing but we should totally hang out again sometime. I wouldn’t mind doing that again, maybe! After all, you took it all down pretty well.” Mimie flirted running her hand over SketchPad’s dark red cheek and then waving goodbye as she began to trot off.

“See you later, Sketch!” She yelled back halfway down the path from the house. A few seconds later an emblem began to glow just underneath her and a moment later she was gone, back down the mountain and on her way back to her home in Ponyville.

SketchPad stood there staring for another long minute before finally closing the door and staggering backward to the center of the living room.

“Did… Did I just—?”

Meanwhile, BluePrint had managed to sneak upstairs and was already in the kitchen collecting the rest of the orange potion that had not been spilt over the counter. BluePrint grinned wide—his gender swap potion had been a flop, but it had become a gateway to a whole new set of experiments rushing through his mind as he slowly inched his way back towards the basement door.

“BluePrint, you son of a—!!!”

SketchPad was standing right in the doorway of the kitchen, glaring right at him.

“Oh buck!” BluePrint gasped out and darted downstairs, his roommate bounding down after him.

SketchPad’s face was completely red. Not only had he just had a horse penis in his mouth—he had actually enjoyed it. This made him even angrier as he chased after his roommate. BluePrint was ecstatic and laughing hysterically as he just barely dodged the outreached hand of the brown colored stallion. There was so much more work to be done and mischief to be made, and he was more excited now than at the beginning of the day when he had first mixed his new potion. His new futa potion would be fun to experiment with. But first, he would have to get away from his roommate.

Author's Note

Thanks for reading. This is my first attempt at a clopfic. I appreciate everyone for taking the time to read through it. Sorry if it doesn't have the right amount of sexual scenes and is devoid of canon characters, but this is something I've been wanting to try for a while so thank you very much for even taking the time to look it over. ^_^