Unexpected Expertise
*Ker-bump!*
Twilight Sparkle felt her body rise up off her seat as the bus suddenly rolled over a speed bump. The startling jolt rocked the whole vehicle as it began to slow down, the bump having finally persuaded the driver to ease up a bit on the gas. Unfortunately, he did so by slamming on the breaks, forcing Twilight to raise her arms and brace against the back of the seat in front of her lest she face-plants into it.
*Grrrooaaan*
Grimacing as the bus decelerated at a more manageable rate, one of Twilight's hands moved down over her stomach. The sudden movement of the bus had reminded her bowels just how full they were right now. Grunting, the young woman quickly clenched her anus, feeling an immense solid boulder pressing up against the interior of her rectum.
With a pained sigh, Twilight glanced out the window beside her. Staring blankly at the passing buildings, she desperately hoped that this latest wave of pressure would end quickly. Both her thighs were pressed firmly together as she squirmed anxiously in her seat. Thankfully, the bus was mostly empty right now so there was little chance anyone would notice her struggle.
After almost half a minute, the pressure finally began to ease up a little. Pushing her glasses up the bridge of her nose with her middle finger, Twilight let out a frustrated scowl. This constipation was insufferable.
She was currently en route to her brother's apartment out in the city. However, with the man himself having recently been dragged out of town by a bunch of his friends, Cadence was the one she was on her way to see this time. Apparently a few of Shining’s friends had dragged him out to some special party or something outside the city for the weekend.
Meanwhile, her soon-to-be sister-in-law had just recently been appointed the new principal of Crystal Prep and was quite eager to talk to someone about it. Twilight just hoped she'd be able to stay out of the bathroom long enough to listen.
The cause of her recent bout of constipation was likely tied directly to another little 'get-together' that she and Sunset had held a little over a week ago. Though technically, she had no proof that it had anything to do with this, the experimental magic pills they'd swallowed that night were almost certainly responsible.
Ever since that messy night, she'd been utterly unable to have a proper bowel movement again. A huge blockage had formed out of nowhere, making it difficult to push out much of anything. Of course, her body didn't seem to care as it continued to build upon the ever-worsening boulder in her colon.
*Prrrrrfft!*
A blush rose on Twilight's cheeks as she was unable to prevent a small wet fart from squeezing past her defenses. Thankfully, it hadn't been loud enough for anyone else on the bus to hear. As of the day before yesterday, finding the nearest bathroom had become an almost hourly event. With that in mind, she'd already been on this bus for much longer than that thanks to Canterlot City’s infamous traffic.
*Prrrrrllrt!*
With a grunt, Twilight clenched her anus even harder, desperately resisting the painful pressure that followed yet another wet fart which she was again helpless to stop.
The worst part of all though was that, despite the overwhelming need to go, she knew it wouldn't amount to anything substantial upon finally planting herself on a toilet. On the other hand, choosing not to resist her body's urges was a surefire way to make a mess in her panties from whatever liquid waste always managed to leak past her bowel blockade.
Getting lost in her worried thoughts yet again, Twilight was left unprepared as the bus hopped another curb while making a particularly sharp right turn.
"Gah!" She yelped, the surprise providing just enough of an opening for her bowels to make another quick push.
*Splart~!*
Twilight's eyes widened as she felt a small amount of diarrhea suddenly squirt through her puckered anus. Warm and slick, the sticky substance smushed between her ass cheeks and splattered onto the inside seat of her panties, likely bleeding straight through her delicate underwear.
A deep blush rose on her cheeks as Twilight found herself somewhat enjoying the sensation, despite the ramifications. She was at least relieved to be wearing a fairly long skirt today. Though, she really hoped she wouldn't be leaving anything behind on the seat...
*Knock, knock, knock, knock!*
"Coming, just a moment!" Cadence called, hurrying down the hall from her bedroom to answer the rather urgent knocking at the front door.
Turning the knob, she opened the door to reveal Twilight standing on the other side. Cadence smiled at the sight of the now grown-up little girl that she used to babysit all those years ago.
"Hey, you're here!" She greeted with a warm smile. "Glad you could make it all the way out here today. You know, I was starting to get worried that you might have gotten los-"
"-S-sorry, but can I use your bathroom real quick p-please?" Twilight abruptly interrupted, surprising Cadence with the strained tone in her voice.
"Oh, uh, yeah sure thing." Cadence nodded, stepping aside.
Darting past, Twilight bolted down the main hall as she frantically searched for the bathroom. Eventually finding it, she tossed open the door and ran inside. A few moments later, a massive bubbly fart echoed from within, leading an amused Cadence to chuckle.
'Wow, she really needed to go, huh?'
With a shrug, Cadence tossed the front door closed and wandered into the adjacent living room. One of Twilight's favorite board games had already been set up ahead of time for the girl’s visit. It was almost a tradition for them to play it at this point. Twilight would get the chance to almost certainly destroy her in one of her favorite tabletop strategy games, meanwhile, she got the opportunity to vent and talk about whatever she and Shining had been up to lately.
Sitting down at the table, she glanced down at the shiny gold ring on her finger, admiring it. Shining likely wouldn't be back home until tomorrow at least, too busy enjoying his 'totally-not-a-bachelor-party' party. Cadence giggled as she imagined her soon-to-be husband walleyed and surrounded by several half-naked strippers.
She was almost jealous.
He knew full well that she wouldn't mind if he did decide to indulge a little more than most married men really should~. Honestly, she'd be a bit disappointed if he didn't nail at least one of the girls before the party was over. Hopefully, he’d tell her all about it once he got back. Though they had never told anyone outside of some close friends, she and Shining had developed a fairly... 'open' relationship over the years of being together.
She had no fear he would ever abandon her or anything like that. They'd been together for years, practically since she babysat Twilight back when she was in her early teens. Yet even after all this time, their love for each other had never faded, not even a little. The warm glow already presents in Cadence's cheeks brightened.
‘Plus, he'd be hard-pressed to find someone as into his secret little fetish as I am~.’
*Fwooshhhh!*
'Well... maybe with one exception...' She pondered, hearing the toilet flush from the hall. 'Hmm... I wonder...'
"Feeling better now Twilight?" Cadence chuckled as Twilight entered into the living room, shoulders slumped as she let out an irritated sigh. The girl almost looked worse for wear than before.
"Kinda... sorry about busting in here like that. I've just, uh, been feeling a bit... blocked up recently." Twilight explained, taking the seat opposite.
"Oh? I suppose that would explain why you certainly don't look like you're feeling much better." Cadence replied, noticing as Twilight shifted uncomfortably in her seat for a moment. She seemed to be leaning ever so slightly to one side.
"Yea... It's pretty bad... but I'm sure I'll get over it eventually, right?"
Despite the girl's hopeful tone, the sad smile on Twilight's face was telling. The poor girl was clearly suffering. Cadence had been constipated herself a few times in semi-recent memory, though luckily for her, a certain large-cocked stud had been quite happy to break up the clog himself~.
"Sooo, Twilight, I’m curious... Have ya found anyone you like at school yet?" Cadence asked casually as Twilight began unconsciously organizing the various colored pieces on the game board between them.
"N-no... not really..." Twilight replied, face reddening slightly as she looked off to the side.
'Ooo, was that I lie just now? Has my little Twilight finally got a crush on someone~?' Cadence thought to herself excitedly.
"Hmm, well that's a shame. You'd be amazed how helpful Shiny can be when I'm feeling down in the 'dumps'. Though, perhaps there's something that I could do to help?" Cadence proposed.
"Er, like what? I've already tried diet changes, enemas, and even laxatives, but nothing so far has worked. I'm honestly not sure that there is anything you can do." Twilight sighed.
Cadence chuckled, "Well, whenever I'm feeling a little blocked up, I often find that a little... physical persuasion tends to help out a lot."
"Huh? What do you mean, 'physical persuasion’?" Twilight asked with a quirked eyebrow.
"Oh, you know, just a little... intimate persuasion~?" Cadence answered in a hushed tone, wiggling her eyebrows suggestively.
"O-oh! W-well, I, uh... I never really-" Twilight stammered, quickly becoming flustered as she realized what Cadence meant.
Truthfully, that was the one thing she hadn't tried yet, though, the idea had crossed her a few times mind given what started her problem in the first place...
"Maybe you should try it next time you get the chance. I promise, nothing helps clear out my bowels like a good orgasm~." Cadence giggled, grinning as she watched Twilight's face light up like a Christmas tree.
'She's so cute when she gets like this~.'
Now that she was thinking about it, with Shining likely indulging himself elsewhere, he likely wouldn't mind if she had a little fun too, right?. An idea quickly began to form in Cadence's increasingly steamy mind.
"W-well, I uh, don't exactly know about all that... s-stuff..." Twilight lied, trying in vain to appear innocent in front of the girl who at one point was Crystal Prep’s biggest school slut.
"Well, in that case, maybe you just need a little help from a very close friend? Maybe even... a family friend~? I may not quite have the ‘equipment’ that my Shiny does, but I'm sure that my tongue would suffice." Cadence casually offered, lowering her gaze suggestively as she reached out and placed her hand over Twilights.
"W-what?!" Twilight gasped, now blushing ferociously as she put together what Cadence was suggesting. "Y-you're saying you'd be willing to... d-do that to me?! While I'm o-on the t-toilet?!" She exclaimed, heart racing.
"Ahuh!" Cadence confirmed with a warm smile. "It's a little different from what Shining usually does for me, but it should do the trick just the same, don’t you think?"
"B-but, what would S-shin- Wait, he does WHAT?!" Twilight yelped, her face somehow turning even redder as she was overwhelmed by a rush of lewd mental imagery.
*Prrrrt!*
There was silence for a moment as Twilight was taken too off guard to stop a loud fart from slipping out.
"Oh, don't you worry about him, I'm certain that he wouldn't mind his fiance helping out his little sister when she’s in need~" Cadence assured with a saucy grin. "You know, if anything, he'd probably want to help you with this himself if he were here."
"He, w-what?!" Twilight stammered, thoroughly flustered. Somehow, she found herself not entirely dismissing the until now unthinkable concept of doing it with her big brother. In fact, she was almost scared of just how much she really didn't mind it.
Cadence giggled at Twilight's flabbergasted expression, eventually reaching forward and cupping one side of the girl's face with her other hand. This silenced her flustered stammering almost immediately as she gulped audibly under her sister-in-law’s seductive gaze.
"You have no idea how many times he's had me dress up as you on for his birthdays~."
It felt as though anxiety was literally oozing from her body as Twilight watched Cadence turn and shut the bathroom door behind them. Turning back around, the woman snatched a small blue hair tie off the marble counter, putting her hair up into a ponytail.
"Go ahead and get comfortable Twily, and I'll be right down to take all that pressure away~" She instructed, giving Twilight a playful wink.
Twilight gulped as she glanced back at the toilet seat behind her. Just looking at it was causing her bowels to stir again and she could tell that another 'assault' was imminent. Yet, the sense of impending disappointment and frustration that usually followed could very well come to an end given what Cadence was proposing...and a very climactic one at that...
Still, she couldn't help but feel incredibly nervous about what was they were about to do. For all intents and purposes, she was about to have sex with her sister-in-law... all just to relieve her constipation. Though to be fair, what Cadence was offering did make some sense, and with Spike still over at Sunset's place for the rest of the week, this would be the quickest way to resolve her problem.
While Cadence finished fixing up her hair, Twilight began slowly taking down her skirt. She paused for a moment before finally discarding it to the bathroom floor. Panties now exposed, she turned and bent down to lift up the toilet lid, forgetting that she was now inadvertently showing off the result of her earlier struggles on the bus. A wet brown streak ran up along the crack of her ass, making it clear that her trip had not been without incident.
"Ohh my~. Looks like someone's already made a little mess in their panties today." Cadence giggled, much to Twilight further embarrassment.
Quickly spinning back around, she was unable to meet Cadence's lustful gaze as she pressed her thighs together. Closing her eyes and taking a deep breath, she finally hooked her thumbs underneath elastic of her semi-soiled underwear. Doing her best to pretend that she wasn't being closely observed, Twilight closed her eyes and slowly began pulling them down. Her heart thumped hard in her chest as she felt the sticky fabric peel away from her messy butt cheeks, causing her whole body to shudder from the cool bathroom air.
Finally separated, she let her underwear fall and bunch up around her ankles. With only a hint of trimmed hair above it, her naked slit was left fully exposed. The pinkish lips of her pussy trembled as she could almost feel Cadence's eyes affixing to her crotch. Opening her eyes and looking up, she immediately regretted doing so as she saw the almost animalistic hunger hiding behind the young woman's eyes.
'I-is this really about to happen?' Twilight thought to herself, still finding this all hard to fathom.
"Say, Twilight-" Cadence suddenly spoke up. "Before we get started, why don't you go ahead and bend over the toilet for me a minute? I think I need to conduct a closer inspection of the problem first."
"B-bend over?"
"Mhm, I'll need to see the problem up close before I get to 'curing you' of it, silly~."
"Um... o-okay," Twilight mumbled, turning around to face the toilet again.
Slowly bending over, her arms propped themselves up against the back of the toilet. Staring down into the bowl below, Twilight craned her neck to peer between her quivering thighs. Her heart skipped a beat as she saw Cadence walk up right behind her and them get down onto her knees.
"Ooo, my my, you really did make a mess on your way here, didn't you~."
Twilight gasped as she felt a pair of hands seize her ass cheeks, slowly spreading them apart and revealing the muddied anus tucked between them. It twitched and quivered as Cadence gave Twilight’s asshole a good looking over, with her eyes occasionally dashing down to admire the girl's slightly moistened slit. Clearly she wasn’t the only one getting excited about this...
"S-so... um... what were you looking for- Ah!" Twilight gasped as she felt a tongue suddenly glide up across her messy anus. "C-cadence!"
"Mmm," The woman moaned, fingers digging deep into Twilight's messy ass as she relished in the rancid taste of Twilight's runny excrement. "Well, you certainly feel all tensed up~" Cadence stated nonchalantly, going in for another lick.
Twilight grunted as she felt the woman’s tongue graze over her anus a second time. The repeated stimulation was enough to finally provoke another surge of pressure from her bowels.
"C-cadence, Its-!"
*Flrrprpt!*
A bubbly fart erupted from Twilight's tight anus right as Cadence's mouth had been wide open, instantly filling it with noxious fumes. Not expecting the sudden outburst, Cadence recoiled instinctively, coughing.
"Oh, my gosh Cadence! I'm so sorry, I-i didn't mean to-"
"No, no! *cough*, Y-your- *cough* -fine Twily, whew. I just didn't expect you to blast me like that, heh~." Cadence chuckled, taking a moment to inhale more of the noxious gas through her nose. "Mmm, well, you're definitely blocked up, but there's one more thing I want to test..."
Before Twilight could ask what that thing was, she again felt Cadence's tongue glide over her now well-lubricated anus. Yet instead of pulling back afterward, Twilight was stunned to feel the tip of her tongue push inside. Feeling the hard bumpy surface of a rock-solid log on the other side, Cadence couldn’t help but gag. The taste was bad enough to finally get her to back away, though it didn't stop her from swirling what residue she'd taken off around the inside of her mouth.
At the same time, Twilight grunted as her bowels pushed hard, causing her anus to gradually widen. Cadence's heart fluttered as she watched a truly massive boulder start peeking out. Yet, the wider and wider the girl's asshole got, the clearer it became that it just wasn't enough.
But even as the enormous log struggled against Twilight's stretched anus, liquidy mush continued to leak out around the blockage. It became all to clear as to how she'd messed her panties up so much on her way here.
"Geeze Twilight, how much toilet paper have you had to use like this? You must be shitting yourself all the time like this."
Twilight didn't answer, too embarrassed to admit that Cadence was right. It had been almost impossible to avoid sharting herself. She had gone through a great many pairs of underwear over the past few days. Thankfully she'd been able to hide her laundry from her parents.
The spectacle Cadence was watching was not long for this world, however. Just as fast as it started, the pressure Twilight felt began to recede. Slowly but surely, the problematic log slid back inside as her bowels as her anus closed quickly behind it.
"Aww, looks like someone's a little shy~" Cadence giggled, feeling a tingle in her crotch as Twilight's anus shrunk back down to its original size. "Don't you worry Twi, I'll make sure you feel all better soon~"
Leaning forward, Cadence pursed her lips, spreading the girl's ass cheeks again with her hands as she delivered one last little kiss to the newly dirtied pucker. Moaning from the unexpected sensation, a fart squeezed out of through girl’s twitching asshole, blasting Cadence's face yet again.
"I-im sorry! I didn't mean to-"
"Shh, shh, shh, it's okay Twilight. Trust me, I really don't mind~"
Twilight's blush deepened as she looked back at Cadence over her shoulder, still finding it hard to believe that her sister-in-law had just kissed her messy butthole. It was a mystery to Twilight how she could withstand tasting something that bad and seemingly enjoy it.
"Now, why don't you have a seat, and I'll show you what I can really do~" Cadence instructed, licking her lips clean as she gestured for Twilight to stand up...
Twilight was really trying to look anywhere but at the woman now crouched in front of her crotch. Properly sitting on the toilet now, her legs were spread wide and her sensitive pussy was left exposed and vulnerable. The effect of countless ‘sessions’ with Spike left her delicate flower looking quite far from unused.
Cadence, meanwhile, was taking a moment to admire the precious sight before her. She was clearly eager to devour Twilight’s non-virgin pussy as she licked her lips in anticipation.
"Now, you just sit back, relax, and enjoy~,"
Twilight felt her body shudder as the woman's cool hands touched her inner thighs, spreading them just a little further apart as she leaned forward for her prize. Heart thumping fast in her chest, Twilight gasped as Cadence's tongue flicked up along her sensitive vulva. Pleasure spread up through her body as a horny cry escaped her lips.
"C-cadence~!"
Encouraged by Twilight's moans, Cadence lunged forward to devour the girl's dripping folds. With each lick, Twilight's bowels had begun to stir once again, causing the girl to grunt as she tried to focus on pushing.
"I-its coming!" She moaned, struggling to keep her composure while being eaten out.
Hearing the desperation in Twilight's voice, Cadence drove her tongue as deep as she could into her pussy. Eventually moving up towards the girl's adorable clit, she playfully tickled the sensitive bud. The pain which Twilight normally felt as she tried to force out the huge log was almost non-existent as Cadence lapped up her juices, replacing it instead with mind-numbing pleasure. It was clear that this was not the first time the woman had done this before.
Small watery plops could be heard as small gooey chunks of poop dropped down into the water, leaking out around the slowly emerging turd. It didn't take very long for Twilight to reach her usual stopping point, yet somehow, her asshole continued to expand.
"C-cadence, It's almost- Gah!"
Suddenly, Twilight’s exclamation was interrupted by a particularly firm lick from Cadence's as she drove her tongue all the way up through the entire length of her pussy. Hands instinctively coming down, she pressed her sister-in-law's face deep into her crotch. The combination of stimuli was overwhelming.
Sliding out bit by bit, the huge blockage in Twilight’s asshole extended further out than it ever had before. As the first few inches of the mighty log craned down into the toilet bowl, Cadence never stopped. Even as the putrid stench of shit wafted up into her nose from the shit coming out mere inches from her open mouth, she didn't stop. If anything, the intense odor only fueled her growing lust as she pictured herself in Twilight’s place.
The wonderful bliss of having her asshole spread so wide by a massive column of solid creamy shit, the indescribable waves of pleasure and relief, and the feeling of her bowels growing lighter and lighter with each passing second. All of it came together to carry her towards an approaching peak of ecstasy as her climax neared.
For Twilight, what had felt like a week of torture seemed to be finally coming to an end. The thickest section of her log had already slid free through her anus as Cadence delivered one last firm lick to her clit. Falling into the murky brown toilet water with a loud splash, what followed could only be described as a volcanic eruption of shit. All the enemas, laxatives, and everything else she'd tried seemed like it was all taking effect at once as an immense torrent of brown magma exploded into the bowl.
Twilight's breath hitched as her fingers dug into Cadence's hair, her whole body tensing up as she finally came. Sticky transparent fluid gushed from her pussy, leading the other woman to moan as she eagerly lapped up the fluids. Head falling back against the wall, Twilight bathed in the afterglow as her bloated stomach deflated, her bowels relieved at last. All the stress and pain was finally over, and boy did it felt amazing~.
Down below, Cadence grinned as she glanced up at Twilight. She almost pulled away to speak, only to pause as she realized that something was wrong. She’d been so focused on imagining the blissful relief Twilight was feeling, she'd been oblivious to the fact that her own bowels had become quite adamant for relief as well.
However, with the toilet very clearly clogged for the time being, she'd need to find somewhere else to lighten her own load. Biting her lip, a naughty smirk grew across the woman’s face as glanced down at the messy panties around Twilight’s feet. Reaching back, Cadence traced her index finger up through the smooth crack of her tight jeans.
"Say, Twilight?" She asked, the girl in question tiredly tilting her head down at Cadence's call. "You wanna see something super naughty~?"
The embarrassed blush returned to Twilight's cheeks as she wondered what Cadence could mean by that. She was not left wondering for very long, however, as a moment later, Cadence began to grunt. Eyes widening, she watched as her sister-in-law's knees buckled, bending inward as a wet crackling sound filled the air.
"Cadence, are you..." Twilight gasped, her assumption confirmed as the unmistakable sound of poop rushing out into a pair of no longer clean panties became quite audible.
Cadence moaned as the seat of her pants expanded way from her cheeks, making room for the landslide of shit rushing through her anus. Warm semi-solid mush spread all throughout the inside of her panties as, before long, she could feel shit oozing down along the inside of her thighs.
Looking up at a stunned Twilight with a sly knowing grin, Cadence stood up from the floor. The flow of poop filling the seat of her pants slowing, she turned around so Twilight could see the gigantic bulge. At the mound’s peak, the denim had turned a wet brown color. Cadence finished off the incredible load with one last grunt, bending over a little and gasping as the already huge bulge almost doubled in size in an instant.
*Frrrraaaaapft~!*
"Ahhh~, now that's more like it~." She giggled, playfully spanking her mushy load and spreading the poop within even more.
Looking up at Twilight's shocked expression, she merely shrugged.
"What? It's not like we were gonna get that toilet unclogged any time soon anyway. Now come on, let's see if you can still beat me at your favorite game now... I'll warn you though, I get can get pretty nasty when I'm all messy like this~..." Cadence chuckled, waltzing out of the bathroom, her hips swaying as Twilight found her eyes drawn to the impressive bulge jutting out from the seat of her ruined jeans.
Feeling a gitty sense of excitement, Twilight quickly stood up and reached down to pull up her panties and follow after Cadence, not caring as her still quite messy butt cheeks further ruined her underwear. She eagerly followed Cadence back to the living room. Indeed, things were going to get quite nasty...