After a long, sweaty moment of rest, Starlight rolled off of Twilight, freeing Limestone from between their bodies. “Twilight,” she said, "if you're ready for another round… I've got an idea that I think might earn me another gold star.”

“Well, that was more than enough,” said Twilight, “but I would never want to discourage an eager student. What's your idea?”

Desperate to be acknowledged, Limestone Pie was about to dig her way through Twilight’s fur to try and bite down on her skin. But Twilight rolled onto her side, to look into Starlight’s eyes, and Limestone tumbled off her body, landing roughly on the table below.

“Well,” said Starlight, “it starts with that spell you cast a few days ago. I think we were in the kitchen that time…”

Twilight grinned mischievously, her eyes too focused on Starlight to see Limestone hopping up and down beneath her. “I know the spell you mean,” she said. “Couldn't get enough, huh?”

“Well, it certainly gave me some ideas,” said Starlight.

Twilight but her lip “I bet. So do you want it this time?”

“No,” said Starlight. “I mean, maybe next time… but for now, can you just cast it on yourself?”

Twilight shifted her body, sitting upright on her flank, and her horn began to glow. Down below her, still beneath the notice of either massive mare, the Pie family rushed into the space between their bodies, surrounding Limestone.

“Fool girl!” said Igneous, “Did ye not hear us yelling for you to stop?”

“I wasn't yelling,” said Maud. “I was speaking in the same tone of voice I always do.”

“‘Twas implied, daughter!” snapped Igneous. Then, turning back towards Limestone: ”It was a noble effort, risking thyself to catch the attention of these two mares. But they are lost in the act of physical love, and our best chance is to wait upon Pinkamena’s return.”

“Well, you can't blame me for trying,” said Limestone, avoiding her father’s gaze.

“I can and I have,” said Igneous. “I know I raised a proud girl, but your safety is a greater concern to me than-”

He stopped speaking as a long shadow fell across him and his family. A long shadow that was growing longer all the time. The shrunken ponies looked up to see something growing, extending, from just above Twilight Sparkle’s pussy. With her magic, Twilight Sparkle was giving herself a penis. A thick purple shaft, already hard, was growing longer, submerging all of them in its girthy shadow. By the time it stopped growing, it was over a hundred feet of mare meat.

Or, from the perspective of Twilight herself, about twelve inches. Still a damn big cock.

“It’s huge…” whispered Marble Pie. Her legs were quivering, although the ground underneath her was still.

If Starlight Glimmer had looked down between Twilight’s legs, she would have seen the trembling Pies in the shadow of her Princess’ cock. But she couldn’t tear her eyes away from the thing itself, the thick purple marecock that had sprouted and grown before her eyes.

“I just have to taste it,” said Starlight, and she crawled towards Twilight on her forehooves. She touched the flared tip with the flat of her tongue, feeling its texture and heat and tasting just a hint of salty-sweet precum. Then she kissed it, wrapping her lips around its girth and taking it deeper, deeper, deeper.

All this played out above the heads of the Pie family, one beautiful giantess tasting and loving the body of another. Drool dripped from Starlight’s mouth, and a thick drop fell into the space between the Pies.

Starlight drew her head back, leaving Twilight’s cock slathered in spit up to the medial ring. “I want to try something,” said Starlight. “Let’s go to Canterlot.”

Twilight shuffled her hips, rotating her body, orienting it towards the seat of Equestrian power. The Pies were caught off guard by the motion; had they started running as soon as they reunited with Limestone, they might have gotten clear before this moment. But Princess Twilight Sparkle growing a cock was an arresting spectacle, and who could blame them for staring in awe?

At any rate, they were still between Twilight’s legs when she began to move, and the huge purple appendages threatened to squash them flat. As one, the family hopped like fleas onto the fur of Twilight’s thigh, gripping as hard as their teeth and hooves would allow.

In a quieter moment, Twilight would likely have noticed the sensation of five little ponies attaching themselves to the fur of her inner thigh. But right now she had two sets of genitals begging for attention and a beautiful unicorn mare eager to provide it. Heedless of the ponies clinging to her, she straddled the mountains overlooking Canterlot, setting her ass down on top of the raised earth. The mountains were holograms like everything's by else, but they were wide and sturdy enough to support the ass of a full grown mare.

The Pie family let go of Twilight’s fur, dropping a short distance onto the mountain slope. They fled down the slope, huddling in the shadow of Canterlot once they arrived at ground level. They stared up, past the high towers of the royal city, to where Twilight’s cock loomed above.

“Twilight,” said Starlight, using her magic to take hold of Twilight’s shaft, “I can never thank you enough for believing in me. For seeing the good in me.” Her magic aura began to slide up and down Twilight’s cock, slowly caressing its length.

“But what if I'd corrupted you?” said Starlight. “Imagine the two of us rampaging and fucking across Equestria. Imagine becoming huge, growing a big fat cock, and then…”

With her magical grip on Twilight's shaft, she brought her cock down onto the castle, smashing it to pieces. “Mmm,” moaned Starlight. “Now who's the ruler of Equestria?” The castle reconstituted itself, and Starlight smashed it with Twilight‘s dick again. “Now who’s the most powerful princess?”

Starlight’s horn glowed a bit brighter, and a magical aura flickered to life around Twilight’s pussy lips. “Oh, Starlight,” moaned Twilight, “I could never… but… but you make it sound almost…” her lips kept moving, trying to form a sentence, but she was quickly moving beyond words. Starlight’s magic was gentle and firm as it stroked her shaft, and it was strong and rhythmic as it pounded against her clit. The mind of a pony simply wasn't made to deal with such a concentration of pleasure, and her body shook violently as the feeling overtook her.

Far below, beneath Canterlot, the Pie family struggled to keep their footing on the quaking ground. Each time Canterlot reconstituted itself, Starlight bashed it with Twilight’s cock, sending holographic rubble crashing to the table below. The Pies couldn't say for sure whether the rubble even had substance, whether it would hurt to be hit by it - but they were taking no chances. They scrambled around on unsteady hooves, diving out of the way of the falling debris.

“Starlight,” cried Twilight, “Starlight, I'm coming! I'm coming!”

Starlight Glimmer grinned, suddenly looking entirely evil. “No you're not,” she said, and a deep red aura settled onto Twilight’s marehood and the base of her cock.

“Aah-” gasped Twilight. “I, I can’t-”

“You don’t cum until I say so,” said Starlight, with a chuckle. “Orgasm denial isn’t dark magic… it’s just very, very cruel.”

“S-starlight,” groaned Twilight, “You have to let me cum, please... “

“Oh, you’ll cum all right,” said Starlight. “Your cock and pussy are going to pop like fireworks, your highness. You’ll just have to be patient.”

“No,” whispered Twilight, “I can’t take it…”

“You won’t enjoy it if you keep complaining,” said Starlight. “Let me shut your mouth so you can just focus on feeling that climax get bigger and bigger inside you…” She stepped closer to Twilight, threw her forehooves over the Princess’ shoulders, and took her in a kiss. Twilight let out a couple more muffled protests, but soon leaned into the kiss, closing her eyes and meeting Starlight’s tongue as her pupil’s magic continued to stroke her cock and vibrate against her clit.

With her attention focused on the kiss, Starlight was no longer bothering to repeatedly destroy Canterlot. This gave the Pies some time to catch their breath, no longer dodging holographic debris, but it was clear the moment wouldn’t last long. Twilight was no longer protesting the spell that was preventing her from coming, but she was emitting muffled moans that were getting more intense and higher in pitch. Starlight would have to let her cum eventually.

But she seemed determined to draw out the suspense. The two giant mares were sitting on either side of Canterlot, straddling it, pinning the shrunken ponies between their bodies. As Twilight’s body shook more violently and her cries became more pained, Starlight became more and more aroused, her pussy dripping a musky pool onto the table. The unicorn was enjoying her Princess’ suffering perhaps a bit too much, delighting in the power she had over her teacher. Twilight’s cock throbbed and twitched so forcefully that it smashed into Canterlot all on its own. Her pussy was clenching, desperate to release its accumulated tension… and finally Starlight let the spell dissipate.

Twilight’s pussy throbbed powerfully, squirting its musky payload through the streets of the miniature Canterlot and creating rivers of fluid down the neighboring mountains. Her upright cock first twitched and shot its first jet of cum, painting a thick white line across Starlight’s chest.

Starlight, feeling the hot streak of cum hitting her fur, broke off the kiss and fell backwards, letting Twilight’s cock fire off into the open air. With her mouth no longer filled by Starlight’s tongue, Twilight cried out as her cock blew its load, shooting in all directions as it spasmed.

Cum rained down on the tabletop, the liquid landing with enough force to stagger the shrunken Pies. They ran for the base of the mountain, closer to Twilight’s body, where the rain of cum was less likely to hit them. They weaved between the shadows of the falling mareseed, struggling to stay on their hooves as drops hit the table like boulders and splattered into musky pools.

They arrived at the mountain, but it wasn’t an easy climb; Twilight’s pussy had drenched the surface, making it slick. But they made it far enough that they escaped the rain of cum - all except for Marble Pie.

Marble Pie put her hoof on a slick patch of the mountain’s surface, and she lost her footing, squeaking in alarm as she slid down to ground level and into a puddle of Twilight Sparkle’s cum. Marble panicked, flailing, but after a moment of kicking her hooves, she found it was pretty easy to stay afloat. Her family rushed to the edge of the cum puddle, ready to mount a rescue - but all that was needed was for Limestone to extend a hoof as Marble Pie dogpaddled over.

“Are you okay?” asked Limestone, pulling her sticky sister free from the puddle.

Marble swallowed a mouthful of cum and looked away bashfully. “It’s sweet…” she whispered.

“She’s fine,” said Limestone.

Twilight’s climax was powerful, and long, but it came to an end in time. “Starlight…” she gasped, “That was… so mean…”

“I know,” said Starlight. “But it looked to me like that was the best orgasm you’ve ever had.” She leaned in and dragged her tongue along the underside of Twilight’s cock, licking up the cum that was drooling from the tip.

“It was… pretty intense,” said Twilight. “But next time you have to warn me before you-”

The door to the map room burst open, and Pinkie Pie charged through with saddlebags slung across her flank. “I’m here!” she yelled. “Sorry I took so long-”

“Pinkie!” shouted Twilight, her wings rising in alarm. “I, I thought were going to be busy today…”

“So you decided to get busy on the Cutie map?” said Pinkie mischievously. “Ooh, and you grew a big ol’ weiner! Looks like your cock went kablooie all over the-” Pinkie’s mind, briefly distracted by the post-coital tableau, abruptly refocused on the reason she’d come to the throne room.

“Oh!” said Pinkie. “Uh… I was planning to set up a, uh… party… thing… in the map room. For when my family gets here.” She forced a smile. “You know. Confetti and balloons coming out of nowhere, the usual Pinkie Pie stuff. Could I… have the room?”

“Uh, sure,” said Twilight. “Do you want us to clean up first? I should wipe down the table…”

“I’ll take care of it!” said Pinkie. “I’m sure you two want your privacy anyway, so… go and… have your privacy… somewhere else?”

“Uh, okay,” said Twilight, hopping down from the table. “See you later.” She made her way out, with Starlight behind her.

Once they were gone, Pinkie scanned the table, looking for signs of movement. It didn’t take her long to see the five Pies hopping up and down at the base of the mountain near Canterlot, and she hopped onto the table to bring her ear closer to them.

“Oh my gosh!” she said, practically in tears, “I’m so, so sorry, I had no idea that Twilight and Starlight were going to come in here and grow dicks and cum all over the place!”

“You can make your apologies later, Pinkamena” said Cloudy Quartz. “For now, simply restore us to our normal size.”

“Of course!” said Pinkie. She craned her neck back and pulled a small brown bottle from her saddlebags. “Just take one of these and you’ll be back to normal!” She pulled the cork from the bottle and turned it on its side, letting little green tablets spill out onto the table.

Limestone trotted over to one of the spilled tablets and nudged it with her forehoof. From her perspective, it was about six feet across, and weighed - she estimated - about two hundred and fifty pounds.

“Yup!” said Pinkie. “Just pop that in your mouth and swallow, and you’ll be right as rain!” She stared down at her family, none of whom were attempting to consume tablets that were physically larger than their entire bodies. “What are you waiting for?”

“...Oh.”

Author's Note

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