“Stand still, dear.  I haven’t finished my measurements yet.”

It was a difficult week for Rarity at the Carousel Boutique.  The heat had kept almost all of her customers away, none of them wanting to bother with the bulky dresses and gowns that had come to define her small business.  But still, there was Lyra, standing center stage on a low podium wearing a simple, but elegant sleeveless dress, its gold satin skirt riding high up her flank to show off her cutie mark.

“Can’t I just sit down for this?” asked Lyra.

“Absolutely not,” Rarity answered flatly. “Now hold still or it’ll look horrid!  These summer fashions are always such a pain to get right.”

During the conversation, Spike walked by the shop in a post-coital daze.  Twilight, still in the library, had sent Spike out to market to buy as much whipped cream as twenty bits could buy.  “I have some more experiments I want to run,” she said with a wink, “but then we’ll have dessert.”  The total came out to ten cans, resulting in a perplexed look from the clerk and Spike’s tiny arms dropping the unwieldy stack twice since he left.  Just as he passed the Boutique, they fell a third time.  One of the cans bounced as it fell, spraying a comically large gob of cream onto his stomach.

“Doggone it,” he sighed, brushing off some of the cream, “how am I gonna get these back in time?”  Then, looking down, an idea popped into his head.

Spike saw his cock was already starting to grow, tipped off by his idea to transform so his arms could get bigger—among other reasons.  Twilight had finally told him that she could change all by herself, but Spike still wasn’t sure whether he could without someone’s mouth.  As he thought, he touched his throbbing cock, exploring the tender veins that riddled its length.  Forgetting the whipped cream was still on his hand, the topping made his cock twitch with approval, its length slipping effortlessly across his palm.  Without thinking, his claw clenched the shaft on his own and his hips thrust forward to complete the first stroke.

“Unhhh!” cried Spike, “I—I hope we have enough cream left over so I can do this!”

Spike dropped to his knees and continued to shove his cock through his creamy green claw.  And sure enough, the change not only began, but accelerated much quicker than before.  His muscles exploded outward in rapid bursts, hammering his scales like tempered steel into large, bulky, angular shapes.  As he changed, his mind filled with the sights, the smells, the overwhelming sensations the day had given him.  He grew tall, his upturned face warmed by the persistent sun as he enjoyed his secret height. As a pressure built inside his asshole, his thoughts then turned to Rarity, and to the gentle kiss she gave him that day at the library.  Riding the momentum, his ferocious taloned feet dug ruts into the grass, and the tip of his cock began to tingle as gobs of whipped cream spurted out of his grip and onto the ground.  

The whipped cream!  

It was then that Spike remembered his purpose, reluctantly letting go of his cock just a few strokes short of satisfaction.  His heart still racing, he got to his feet and hurriedly reassembled the stack of cans, five under each arm.  The sooner he got back, after all, the sooner he could finish.  But it was as he turned toward home that he happened to glimpse inside a window of the Boutique.

There, Rarity and Lyra were continuing their work, their backs turned to him.  Rarity’s smooth white flank was in plain view, and when she stooped to retrieve her tape measure, her soft, clean slit winked at him, just visible enough to excite Spike further.  He didn’t need to rub himself anymore; his cock was pounding harder than ever, and he began to worry what would happen if he reverted without being inside someone.  But the thought then began to thrill him, and with rapid breaths, Spike’s mind embraced a more daring thought the very moment he thought of it.

He wanted—no—he needed to be inside her.

Secure in his purpose, Spike felt controlled by it, unable to stop himself.  He let the cans fall to the ground and made a move to the front entrance.  He turned the knob and stepped inside, the dragon faintly aware of the bell ringing as the door opened, then closed behind him.  Past the point of no return, Spike’s heart pounded even harder, his cock tingling and primed to explode, a drip of precum falling from the tip and onto the welcome mat.  He felt dangerous, and he projected the same.  Lyra spotted him first, her face aghast as she stared at the monstrous creature who entered.  Rarity, still with her back turned, hardly noticed, unfurling her measuring tape with her magic.

“I’ll be right with you, dear,” Rarity chimed. “And thank you, Lyra, just keep standing still like that and we’ll be done.”        

Undaunted, Spike walked nonchalantly up to Rarity and got on his knees behind her, close enough to hear her hum the first few bars of “The Art of the Dress.”  Leaning forward as stealthy as before, he gave two short sniffs, absorbing her rich scent and making it a part of him.  He then brought up his claws, his mouth salivating as, for a moment, he savored the tension.  Then, all at once, he grabbed her asscheeks roughly in each claw.  Rarity screamed, her body moving under his claws as she dropped the cluster of fabric and scissors that levitated before her.

“EEEK!” she cried, “What in the world—”

But before she could turn around, Spike shoved his face between her cheeks, his tongue slathering all over her waking snatch, rushing over it quickly from bottom to top.  By the end of the first lick, Spike could taste her for the first time, the musk of her sex mixing with the expensive perfume of her coat to create an intoxicating odor that seemed to grab his face and ram it back into her once more.  Rarity screamed much louder, her buttocks clinched around Spike’s face as he licked her.  Lyra fell from the pedestal and onto her back, and she stared wide-eyed at the assault commencing before her.

“Unhand me this instant you—EEEK!” Rarity screamed when Spike licked her again.  Rarity tried to trot away, but Spike inched her kicking hind legs off the ground.  As she looked behind her, Rarity rolled and fell onto her back, releasing her legs from his grip.  As her ass fell from Spike’s face, she lay stunned and, for the first time, vulnerable.  Never looking from his face, her brow furrowed, and words trembled from her lips: “Spike?  Wh-whatever do you want?  What are you doing?  What happened to you?”

“Isn’t it awesome, Rarity?” he said breathlessly, gesturing at his new body, “Twilight showed me how to do it.  And here,” he said, grabbing her right-rear leg and yanking it into the air.  “I can make you just like me, just watch!”  Spike kissed her just above her hoof, then again a couple inches higher toward her knee.  Rarity screamed again, but this time ending with a whimper that dampened the noise.

“No, no, no—” pleaded Rarity.  But Spike maintained course, giving her one kiss after another in rapid succession.  When he reached her inner thigh, she shuddered, and a small squirt of juice trickled from her pussy, the soft pink lips squeezing out to reveal her marehood.  Her white face blushed visibly and she made a strange noise when she exhaled.  Rarity whole body tingled, then quivered, and a nagging voice in her head was telling her to shut up, to embrace the strangeness of the sensations.  But still she tried to resist.  “No—nooo–” she cooed quietly.  Spike could delay it no longer.  His tongue flicked out, fully three inches in length, and slipped between her tender pussy lips.  His face quickly followed, shunting hard against her pubic mound.  “—oooooooohhh—ooh, Spike—ooh—Spike—”

Her elegant voice started to trail off into squeaks, tears welling in her eyes as the horror of it all was met with a strange desire to prolong the misery further.  Confused and exposed, her defenses failed completely and she lay limp, allowing Spike to grab her other leg with his free hand.  He then hoisted up her hind quarters, allowing his face to push harder against her soaking marehood.  The more he licked her, the more her juice trickled down her inner thighs, tacking into a growing puddle that shone brilliantly on the cool tile floor below.  Spike devoured the juice with fevered determination when he noticed how much it also tasted like rubies, sapphires, and a hint of emerald.

“Oh, Spike,” she moaned, “oh Spike!  I had no idea you could—d-do this to me!”

The more Spike licked, the more Rarity felt her body begin to change.  Her breasts were the first to grow, larger and larger they became as they shook lazily against the subtle movement of her body, the rise and fall of her breaths.  Her trembling white hooves met the tender purple nipples as each hoof reformed and smoothed out into hands, new fingers caressing each shape in clockwise circles.  Her body soon extended taller than Twilight’s, squeaking along the sweat of her furry backside as its curvature changed.  Her hips stretched next, growing fuller until they formed a near-perfect heart shape with Spike’s head as its tip.  Finally, errant strands of short blue hair grew and coalesced above her marehood, forming a short rectangle that pointed to the tender little clit beneath.

Fully transformed, she pushed herself up with her hands, forcing her hind quarters to fall from Spike’s grip.  He stood dumbfounded at the creature now before him, her hand softly cupping his right cheek as she leaned in, turning her head to the side.  The two kissed deeply, her tongue slipping between his jaws to taste the juice he had taken from her so roughly just moments before.  Spike let his hands wander as well, large hands rubbing the smell of sticky sex into the back of his lover’s expensive blue mane.

Across the room, Lyra felt invisible, forgetting that she herself was there, until she suddenly felt a soothing cool sensation against her hooves.  Looking down, she saw front hooves were, in fact, hands, as her body was already in the final stages of transforming.  She smiled deliriously, bringing both palms to her face, admiring each digit as they fluttered to her will.  Looking down, she saw a v-shaped tear begin to form on the front of her dress where new breasts had pulled the soft fabric past the breaking point.  She grabbed onto the half-exposed mounds, their nipples aching as they pushed beneath her touch.  

Her growth had also caused the dress to hike up above her waist, where she felt a heaviness at her exposed loins and the sensation of sitting in something wet.  Her right hand zipped down to investigate, and she shivered as her fingertips grazed over a growing tangle of golden pubes pulled taut by the nerves beneath.  She sucked the index finger of her left hand and bit the tip, then felt the middle finger of her right hand flick her swollen clit.  

Her legs scissored shut to her touch, clamping over her hand as she moaned to the ceiling.  Her left hand fell from her mouth and, reaching just below her neck, ripped apart the front of her weakened dress, letting her breasts spill out into view.  As the tattered fabric fell from Lyra’s body, her hands relentlessly kneaded the curves beneath, and she watched with hungry eyes as Spike rolled Rarity onto her stomach.

Spike lifted Rarity’s trembling ass until she was on her knees.  Holding her tail above her in his left claw, his right claw slipped over the curve of her right buttock, then down and over her pussy, slow enough to collect a modicum of juice on his leathery digit as the talon sank inside.  Rarity moaned as the razor-sharp talon eased back out of her, then carefully slid up her taint just hard enough to make her feel an unnerving pain.  

After a few torturous seconds, she felt the talon tap the edge of her tight white asshole.  With an agonizingly slow speed, Spike traced a line of juice around the edge, then rubbed it in over the top, coating the hole thoroughly.  He leaned in and gave the hole a light kiss, feeling her fur stand on end as his lips neared.  Rarity’s white body quivered, her legs stepping outward, her tail now holding itself upward in anticipation of something she knew not of, but desired nonetheless.

“I let you stick me with your pins,” said Spike as his left claw slammed down next to Rarity’s side.  The thoughts that filled his mind excited him so much that he could feel himself slipping.  More menacing thoughts came to mind and he could no longer hold them back and keep from forming them into words.  “Now it’s my turn to stick something into you.”  She could feel the tip of his cock pressing at her asshole,  the first few centimeters already easing inside on the gathered slickness.  “And you’re gonna feel it!”

With sub-glacial speed, he slid his cock into her.  Rarity bit her lip and pushed her upper body upward, her breasts shaking to a stop as he entered her.  “Oh Spike, oh Spike, oh Spiiiiiiiiiiiike–!” she cried, writhing into herself as inch by inch, the dragon cock throbbed into her, her body expanding obediently to let him in.  Her eyes were full of tears, a mix of agonizing pain and newly-discovered pleasure, and as Spike lifted her upper body upwards, her tears shook off and landed on her breasts, trickling down the fur.  It was only a moment before Rarity’s back slapped against Spike’s chest, her arms instinctively reaching behind her as his face buried itself in the crook of her neck.  He nibbled the spot playfully, then soothed it with another wet kiss.  And between them, Spike’s cock pounded inside her ass, never withdrawing more than an inch in a series of shallow, halting strokes.

Lyra rubbed herself vigorously as she watched Spike and Rarity do the same.  She could see Spike’s hands slip between Rarity’s breasts, then down between her legs, where her hands met his and pushed them into her.  Lyra stirred her pussy relentlessly, her sweaty palm scrubbed by her golden bush, letting more and more of her fresh juice dribble onto the rag pinned beneath her ass.  She then saw the two of them fall backwards, Spike landing on his back as Rarity fell forward, then pushed herself upward, rocking her hips against his lap.  As she rode him, Spike’s face contorted, and Rarity’s jaw opened wide, her eyes closed tightly and a blue aura swirling about her horn.  Lyra moaned, then fell down as well, her feet planted on the floor as her hips bucked upward, putting her pussy on full display, hoping for reasons unknown to her that the two would take a look.

“I—I think it’s gonna—” Spike started when, all at once, his cock exploded inside Rarity’s ass.  Rarity’s body jiggled as the dragon filled her, the thick cum splashing deep inside of her.  Another pulse, and then another, and the excess quickly squirted out of her, coating Spike’s throbbing cock.  Soon after, Rarity grabbed Spike’s right hand and pressed it hard against her loins, screaming as her pussy released as well, their fingers trembling side to side over the spot as her own cum sprayed everywhere, coating the insides of Spike’s toned legs.  The noise sent Lyra over the edge, and she squirted even harder, a large trail of translucent goo thwacking onto the tile, then another a few inches short of the mark.

As the moans subsided, Rarity’s body began to shrink, and she fell forward on all fours, letting Spike’s cock flick free.  Lyra, too, scooted backward, savoring the final moments of her beautiful hands until all the digits fattened and disappeared, merging together into her familiar monochrome hoof.  

At last, Spike, his body further weakened from all the day’s exertions, finally returned to his old shape.  But, inside his nonthreatening form, he felt changed by the experience down to his very core.  Unlike that time on Spike’s birthday, the dragon Rarity once knew was now gone for good, and both of them knew it.  For Rarity, in Spike’s place stood the nameless beast who, by force, had made her his.  And, for all she knew, he was capable of anything.

With narrowed eyes, Spike stood over her, looking at her sex-tattered mane, her once-immaculate coat now wreathed with sweat as it rose and fell to struggling breaths, her throbbing asshole dripping with his cum.  When she turned around and looked at him with bedroom eyes, the old Spike would have felt sorry for her, and for what he had done.  But such thoughts never reached the dragon.  Instead, he just pointed at his cock.

“Yes, Spike,” Rarity said, sliding slowly over to him.

“Call me Master,” he said gruffly.  Rarity stopped and bowed her head.

“Okay—Master—” she answered into his lap.

Rarity leaned forward and, with a gentle slurp, sucked his cock back into her mouth.