Relationships are like Geodes

by Silver_Scroll

Rating: mature
Tags: My Little Pony: Friendship is Magic, Marble Pie, Romance, Porn, Limestone Pie, Sex, Slice of Life
Length: 3055

Limestone is a rough pony to be around. She only opens herself to the mare she loves. That mare happens to be her sister Marble.

Limestone and Marble Pie have a secret. That secret is the reason why, ever since the Pie children had been given the chore to watch the farm while the parents went to market, they are the only two that insist on performing these same duties to this day, allowing the rest of the family a trip to town.

The reason is that the two are lovers. And when the family gets back early one day, it is Marble who doesn't want to let that stop their secret couple time from happening. After all, no one else knows how to get her off like her own sister...

Last-minute entry for the April 2019 Incest is Wincest contest

Published 2019-05-01 06:30:01 UTC
Last updated 2019-05-01 06:30:01 UTC

They take unexpected turns

"Alright, they're gone," Limestone announced, her rough voice as grating as ever, and her brow furrowed as it always was as part of her permanent scowl. A casual observer would have thought that she was displeased. Her sister Marble knew better.

"M-hm!" the only other mare still on the farm, who was standing a little ways behind her sister, agreed, smiling warmly while looking towards the other mare. At first glance, it would have seemed like she was reading her sister's face, but her eyes were firmly locked onto something else, right around her sister's gray tail. Something that more than announced the mare's true feelings of excitement.

Without another word, Marble Pie turned around and trotted back towards the house. No yelled commands were needed on the part of the self-proclaimed bedrock of the family, Marble simply expecting her to follow. And once Limestone realized that Marble had started moving, she quickly hurried after her, her scowl deepening while her tail flicked in annoyance, almost concealing a slight wink. It had been too long.

Usually, the two mares would have waited longer for their family to depart. As impatient as they were today, neither of them noticed the cart returning over the horizon moments after their observation ceased.

"You really need to stop hurrying off like that!" Limestone scolded her sister, catching up effortlessly and falling into step beside her just before they reached the house. Marble simply smiled, the normally innocent expression gaining a hint of a smirk as she pushed open the door. Limestone scrunched her muzzle as she tried to think of a retort to the silent challenge, and growled when she couldn't find one beyond claiming that she was in charge. That never worked, and got even less effective the more often she said it. "Let's just get up to the bedroom already."

"M-hm!~" Marble agreed immediately, and practically bounced down the hallway, deliberately keeping her tail raised for the only mare she shared that part of her with. Limestone blushed at the sight, instinctively lowering her head like she'd learned to do whenever she caught a glimpse while working out in the fields. It wouldn't do to be caught staring, let alone reacting like that...

She shook her head and hurried after her sister, letting the door close behind her. By the time she reached the bedroom, Marble was already spread out on the bed, her eyes half lidded and biting her lip in a nonverbal invitation for her sister to join her. "Alright alright, no need to be so pushy," Limestone grumbled, taking a deep breath before climbing onto the bed herself. Things usually got intense with Marble, and she wanted to be prepared.

As soon as they were side by side, Marble leaned in and pressed her lips against Limestone's, letting out a contented hum when Limestone immediately began returning the kiss, closing her eyes to more fully enjoy the feeling. Both mares' hooves began to wander at the same time, caressing each other's bodies and slowly drifting lower, though it was Marble's hoof that reached Limestone's flank first, giving it a squeeze that made the mare huff into the kiss. Marble drew back in response, breaking it, and tilted her head quizzically, though her continued smirk clearly communicated that she knew exactly.

"Oh, just get going already..." Limestone groaned, squirming her hindlegs to try and deal with the rising heat and wetness between them. Marble's grin widened, and she slowly dipped down, planting small, playful kisses along the length of Limestone's body that made her groan and spread her legs in anticipation. Closer and closer, until the very next one finally - Limestone's eyes shot open when she heard the sound of the front door slamming from downstairs, frantically looking towards the window. "No! Why are they back? They shouldn't be back!" she rasped frantically, frozen in place as her mind raced while trying to deal with this development.

Marble had frozen in place as well, her muzzle just a hair's breadth away from her sister's marehood. Her expression seemed more contemplative than panicked though, and so she was also the one who moved first, shuffling off the bed and rising to her hooves. Limestone's frown deepened, unnoticeable to anyone but her own sister, and she sighed. "Yeah, we should probably see what they want," she started, moving to also leave the bed as Marble stepped towards the door - and instead of stepping out, swiftly locked it.

Limestone paused at this new unexpected turn, raising her eyebrow. "Marble, what do you think you're doing?" she asked, the uncertainty she felt at losing control to her sister in situations like this creeping into her voice for the first time. Marble, when she turned around, did not visibly express any image of dominance, merely blushing harder than before and bearing a smile that might have remotely resembled a grin.

By her standards, she may as well have been cackling and baring her teeth in a mad expression of joy. Limestone gulped. "Hey, we said we wouldn't do this when they're around. You agreed!"

Marble merely replied with another "M-hm!" as if that explained anything, and climbed back onto the bed. Limestone tried to close her hindlegs, but Marble pried them apart easily, Limestone unable to muster her full strength to resist what she secretly wanted to happen, at least in part. She bit her lip as she tried to think of another objection that might stay the ravenous shy pony at her nethers, but was forced to gasp instead as Marble kissed her for the second time that day, but on a different set of lips.

Marble didn't hesitate to use her tongue in the kiss this time around, letting out another contented hum that felt heavenly against Limestone's folds and bade her groan and arch her back against the bed. Her attempts to squirm away were quickly halted by Marble hooking a forehoof around her haunch, pulling her closer. Her eyes were closed as she lost herself in the feeling of giving pleasure to her sister, reaching back with her other hoof to start pleasing herself. Limestone groaned again, wriggling from side to side as her legs gave little instinctive kicks.

"Are you both quite well in there?" Limestone drew in a sharp breath at the clear voice right outside the door. What if they had heard? What if she would be unable to control herself? Of course, Marble chose that very moment to change the angling of her muzzle, beginning to let her tongue idly brush against her sister's clit as it wandered. If Limestone had been squirming before, now she was writhing, hissing her breaths past grit teeth in a desperate attempt to not make a sound that her parents would hear.

"Mm~hm!~~" Marble answered the question, freely letting her own moan of pleasure creep into the reply. There was a long pause after that, but if her mother suspected anything, she didn't allow it to color her voice.

"Didst thou or didst thy sister wish for any other purchases from the market whilst we were gone? We were forced to return for my fair husband had forgotten the coinpurse, so if a thought entered your minds during this time, now be the opportunity to speak it!" the older mare announced as cheerfully as was possible with her overly stilted manner of speaking. Marble, being wholly content at the moment, didn't bother answering, instead pushing her tongue deeper to taste more of the mare she loved despite the circumstances of their birth. Limestone's eyes had begun to tear up, and she couldn't have answered even if she wanted to.

For several very long moments, or at least they seemed far too long from Limestone's perspective, the question hung in the air, the silence only filed with the two siblings' huffs and the wet slurps of Marble's tongue against Limestone's marehood. Limestone began whimpering softly as the worry of the silence seeming suspicious grew, and she was just about to risk opening her mouth when her mother spoke once more.

"Oh goodness! I see I have found thy missive listing what I had asked. I shall disturb thee no longer!" And with that, the hoofsteps retreated back down the stairs, the paper that Marble had stuck to the door just in case having satisfied whatever questions the mare might have had. Limestone puffed out a huge breath of air, the relief at not being discovered flooding through her body - and mixing with her arousal into a potent mix. She hurriedly grabbed the pillow and buried her face with it, even biting into it to muffle the moans rapidly rising in volume as Marble methodically repeated the same lick over and over now, steadily and surely moving Limestone closer and closer to her peak.

When she finally reached it, Limestone was lucky she had grabbed the pillow, or the scream would have echoed throughout the entire Pie residence, and all hopes of secrecy would have been utterly and completely lost. As it was, the only pony that witnessed her outburst was the very mare that had caused it, and Marble couldn't have been more pleased as she slurped up her sister's juices, lapping them up as if they were the sweetest nectar fit to delight the Princesses themselves. She let out a shaky huff of her own, the situation getting to her too.

Mercifully, she withdrew when Limestone's peak had concluded, and the usually brash mare simply gasped for breath as she placed the pillow aside, her chest heaving with the effort of getting her breathing back under control. She found her thoughts going over what had just happened, finding herself even more out of it than usual - thanks to a more intense orgasm, she realized as she went over the fresh memory in more detail. But why? Marble also seemed interested, her inquisitive expression this time not undercut by a playful smile making it rhetorical.

Limestone looked towards the door again, faint sounds still audible from down the staircase beyond. The feeling of being so close, so at risk of being caught and exposed... she shivered again just thinking about it. It had been exhilerating. The idea of actually being found out still terrified her... but the terror itself, stopping just short of truly being exposed, was making her wet all over again. Marble caught her glance, observed her reaction, and resumed smiling again.

"Oh, shush, you couldn't possibly have known," Limestone protested against Marble's silence, folding her forelegs in an ineffectual attempt at appearing defiant. Marble simply held her expression, and before long Limestone was forced to sigh in defeat. "Do you think, when our parents told the children to watch the farm so they could go to market all those years ago, they even considered something like this might happen?" she found herself asking, Marble's disarming silence lowering her inhibitions to share random thoughts to make up the difference.

Limestone briefly wondered whether it had been a dumb question, but Marble seemed to pause to consider it seriously, and then simply shook her head, her smile having returned to its usual faint curve it had when she was simply happy. "What about when we were the only ones who still kept insisting on it?" Limestone pressed, her slightly discombobulated mind now chasing after trains of thought she wouldn't usually entertain. Or maybe refused to. "What if they suspected something there?"

Marble had to pause there, and Limestone was dismayed to see the pretty smile fade, and she found herself missing the adorable bounce of Marble's mane when she shook her head before even registering what its absence meant. Instead, Marble had to venture for a shrug. Limestone nodded in agreement, no words necessary even on her part to express that sentiment. But then she pressed on.

"Well, even if they had, they never said anything. So as long as we don't get caught, nothing changes either way, right?"

Marble considered this for a moment, and then smiled again, letting out a cheerful "M-hm!" that made Limestone's heart skip another beat. This was why she'd felt drawn to this mare in the first place. Why no informed wrongness of their relationship had ever been able to sway her. How could loving a mare so pretty and sweet as this one be bad?

Overcome by this thought, Limestone propped herself up onto her haunches and placed a hoof beneath Marble's chest, raising her up so she could meet her in another kiss that lasted almost as long as the first one. "Don't think you can get away without getting your own pleasure as well," she said when she drew back, playfully allowing her usual growl to reenter her voice. Marble squeaked and blushed in response, but didn't stop Limestone when she leaned down to bring her muzzle close to Marble's absolutely soaking pussy for her turn.

"We shall be departing within the minute!" their father shouted from downstairs. "Willst thou and thy sister be alright until our return's time?" Only a few minutes prior the interruption would have caused Limestone to freeze and possibly panic in response, fear gripping her mind and filling it with worst-case scenarios. Now, though, her tail merely raised itself higher as she let the thrill of keeping what she was doing a secret course through her, only further fueling her lewd desire.

"Just get going already, or it'll all be sold out!" she shouted back instead, blushing at the realization that she was basically yelling her answer to her parents at her sister's dripping crotch. "You're lucky I need to stay here and guard the farm, or I'd take charge of going too!" It was an empty threat and they all knew it, Limestone immediately putting it out of her mind and diving into Marble's quivering pussy instead, no longer able to hold herself back.

Marble wasn't nearly as good as keeping herself silent with another mare eating her out as Limestone had been, little moans escaping her lips with every rapid breath as Limestone lapped away. Those tiny moans, each one as clear as a ringing bell, had been what had removed the last doubt in Limestone's mind back when she had heard them the very first time, and to this day she couldn't get enough of them, pressing in deeper with no regard for the marejuices soaking the fur of her muzzle as a consequence.

She was almost sorry to hear the cart being set into motion again outside, the thought that her sister's pretty moans might have been heard having made them seem even sweeter, but as things settled into their familiar environment, the way they should be, the resulting comfort warmed her even more than the excitement of danger had. She began to moan again as well, and angled her tongue more deliberately, targeting exactly the places that she knew would make her sister practically melt from bliss. She was already part of the way there, her tongue hanging out of her muzzle and one hindleg kicking softly in the air.

Sure enough, once Limestone adjusted her technique, Marble's moans actually rose in volume, the mare making the loudest sounds any pony ever heard her make, and only one pony had ever heard - the very mare always causing them in the first place. Marble's breaths quickened, and she grabbed onto Limestone's head for something to hold onto, only pushing her sister's muzzle deeper and making the tongue's work easier. Over and over it assaulted her most vulnerable spots, until at last her pussy lips quivered, and the mare felt herself going over the edge.

With most mares, the moment of their orgasm is the loudest they ever get, or it is at least somewhere along the volume scale that they went through during the course of getting there. Marble, however, didn't seem to have a volume setting as loud as she wanted to get as the pleasure coursed through her body, the petite mare tossing her head back and opening her mouth wide, but letting out an entirely silent orgasm, other than the sound of her gasping breath and the wet grinding of marehood against muzzle.

It was all Limestone needed to know that she had satisfied her sister, and just like Marble had been hungry to gulp down her juices, Limestone savored Marble's as her reward, taking large, deliberate gulps that could easily be heard in the absence of loud moaning that would usually occupy such a moment. She felt Marble's orgasm intensify in response, which was always something that only encouraged her further. She only relented when she felt Marble shiver with the telltale single moan that always signified the transition from peak to afterglow, and she settled back onto her haunches again, waiting to meet Marble's gaze to take one final gulp that unlocked a second small moan, higher pitched than the first. Limestone had been very proud when she'd been able to manage that for the first time.

This time, though, she simply smiled, the usually gruff face softening up in a way rarely seen outside of a bedroom with only her favorite sister. "Want to rest a little bit before we go for round two?"

"M-hm!~"

"Dost thou ponder that they may hold the belief that we are not aware of their union? Should one mayhaps seek to clear them of their error?"

"Leave them be, oh love. Rocks break when they are tapped."

"Should the inside of this rock not be brought forth to shine, least within the trust of family?"

"One may even consider the most splendid geode, a split one of their kind still has their splendrous inside splintered to change who might gaze upon it. Let our children be."

"Thou art wise as always."

"'Tis why the stone chose us. I speak sense, thou listenst~."

"Thou werest the one to leave them to become as they are."

"And wise it has been, seeing what joy has come of it!"

Igneous could no longer argue with his wife's logic, and simply continued to pull the cart.

Author's Note

If you liked what you read, I'd be very happy about an upvote, and regardless: thank you for reading!~