“Ugh - Must we?” Princess Cadance groaned, rolling her eyes.

“Of course not, fair Princess,” Chrysalis chuckled, demurely holding a hoof to her snout. “You can simply concede your husband to the superior mare and spare yourself the indignation of defeat.”

“Honestly, the only reason I even bothered obliging your little request is because you refuse to leave him alone!” the alicorn huffed. “First you brainwash the poor stallion and tried to marry him, while traipsing around disguised as me, then you had the gall to kidnap all of the royalty in Equestria and what do you do?” she continued, boldly jamming a hoof into the shapeshifter’s chest. “You go after him again!”

It was true - time after time, the changeling matriarch had attempted to make off with her beloved. Regardless of the willy bug-horse’s machinations, no matter how close she’d come to overthrowing the ponies’ empire, Chrysalis had made a beeline for Shining Armor time and again. Realizing it likely wasn’t going to stop, Cadance was pushed to her wits end.

It was bad enough that she had to keep an eye on Flurry Heart, protecting the alicorn foal from any ne'er-do-wells, but she’d grown increasingly paranoid about her betrothed’s well-being. Shining was a good stallion, faithful to a fault, but she’s often wondered what the despicable changeling had done with him after he’d been kidnapped. The stallion had denied any wrongdoing, of course, yet she wasn’t convinced.

On one hoof, Cadance knew her spouse had no reason to lie; but, on the other, she was keenly aware of his personal tastes in mares. Ever since she’d known him, he’d been exceptionally forward about his fondness for plump posteriors - particularly those with a pronounced pucker. Knowing the deposed changeling Queen also possessed a booty rivaling or possibly eclipsing her own, she hastily concocted a plan.

Thought it wasn’t easy, requiring her to get assistance from Thorax and his hive, she was able to deliver a message to Chrysalis. The Princess of Love and Changeling Queen would hold a competition to see who was more deserving of Shining Armor’s affection. If Cadance won, Chrysalis would leave the couple alone and seek conquest elsewhere - however, if Chrysalis won, Cadance would have to leave her lover in the shapeshifter’s porous clutches.

After agreeing upon the fine details of their contest, the mares waited to square off. They would use Cadance’s bedchamber, while Shining was off on patrols, to have some privacy for the confrontation. Fortunately, Chrysalis’ shapeshifting abilities allowed her to sneak into the castle undetected, making a mockery of guard staff and the security measures, so nopony knew she was even in the palace.

Standing within Cadance’s room, each eyeing the other from head to hoof, the alicorn and changeling slowly circled one another. Both the mares were paragons of beauty, though each held their own unique appeal. Where the pony was short and held a matronly air about her, the changeling was tall and practically reeked of lustful intent. Like two diametrically opposed sides of the same coin, they scowled.

“I must say, I can see why Shiny would be interested in you,” Chrysalis snickered, examining the alicorn’s backside. Much like herself, the pony’s prominent backdoor sat nestled between her pillowy buns.

“Don’t call him that,” Cadance growled, her eyes locked upon the swollen looking ring of flesh on her opponents tush. Dark and inviting, the glistening torus winked at her, as if sensing her attention.

“Glorious, isn’t it,” the shapeshifter laughed, drawing to a halt. Balancing on three legs, she reached back and caressed her derriere.

“I...it’s not that impressive,” Cadance stammered, knitting her brow. Turning to face the shapeshifter, weary with the pleasantries, she pointed to a satchel slung around the bug-horse’s neck. “Is that it?”

“The very one we agreed on,” Chrysalis affirmed, levitating the bag over her head and to the nearby mattress. “Though, I have to admit, I’ll be shocked if you can handle it,” she added, giggling to herself.

“And I’d be surprised if you couldn’t, Tramp,” the alicorn hissed, trotting over bed. Igniting her horn, flipping the satchel open, she used her sorcery to remove its bulky contents. As the concealed item came into view, she gulped.

The specifics about their battle were as simple as they were scandalous. The two royal mares would fuck one another with the biggest, longest, most imposing double dildo that Equestria had to offer. The mare who came first lost - it was as straightforward as that. Of course, a trial involving a dong of such colossal magnitude would be nearly impossible for vaginal insertions. Fortunately, neither Cadance nor Chrysalis had any intention of ruining their wonderfully taut marehoods...

The alicorn and changeling were, beyond question, two of the biggest anal sluts in all of Equestria, even if neither of them was fully aware of it. Cadance had pounded and toyed with her ass since she was in high school, swearing to save her virginity until she was married. Even after being wed, she preferred to get her booty plundered by Shining’s hot stallionhood. Needless to say, all the wear and tear on her backside left it extraordinarily pronounced and well trained.

Chrysalis, on the other hand, was simply a deviant. Part of her loved the notion of using her exit as an entrance, oftentimes allowing changeling after changeling to ravage her tush. Sweet Tartarus, she’d cum more from having her butt stuffed than from any other form of stimulation and, as such, had developed a glistening donut of soft, inviting flesh. Anal aficionados of varying species, from all around the globe, had sought her out to slake their lust with her well used hole and she’d drained every single one - including…

“I didn’t hear your dear, sweet husband flinging such insults,” Chrysalis chided. “In fact,” she added, a predatory grin slowly splitting her features, “I believe the only he called me was Mommy.”

“Fucking whore,” Cadance barked, her temper flaring.

“Guilty,” the changeling mirthfully rebuked, flipping her mane to the side. Crawling onto the bed, moving to the center of the mattress, she eased herself down and laid on her side. “Come now, little alicorn, must we have such animosity towards each other?”

“You fucked my husband…” the Princess grumbled, warily joining the shapeshifter on the opposite side of the pillowy surface.

“Oh no, you’re quite mistaken. You see, Shining was more than content fucking me! No spells, no changeling witchcraft, he just…” she faltered, reminiscing on the sensation of his throbbing stallionhood in her behind, “has excellent tastes.”

Mirroring the changeling’s position, glaring over at her foe, Cadance grimaced at the harlot. Appraising the licentious bug-horse, she had to admit, there was a certain licentious appeal to Chrysalis. Debased and megalomaniacal as she was, there was an undeniable air of sexuality about the shapeshifter. Gazing lower, her eyes came to rest upon the titanic sex toy.

Nearly as long as her leg and virtually double the width of the average stallion, the two headed dong could easily be mistaken for a gag gift. While it was true that few, if any, creatures could accommodate such a massive dildo, Cadance had seen no other way to settle her dispute with the evil Queen. Considering both of the mares sat at the apex of anal aptitude, she knew her only chance was to push the changeling’s limits.

Spying what held the alicorn’s attention, Chrysalis chuckled and slowly turned in place. “I’m surprised you got one so modestly sized,” she hummed, bringing her face to the floppy shaft. Truthfully, she couldn’t recall having her backdoor serviced by something of that size, but she wasn’t about to admit it.

Dragging her tongue over the textured length, her muzzle crept to one of the flared ends. Positioned as she was, facing the opposite direction as the Princess, she had an exquisite view of the pony’s derriere and the ripe, dark entrance seated behind the alicorn’s marehood. Enemy or not, the captivating sight caused her mouth to water. She’d had every intention of getting things lubed up for their little challenge, although that didn’t mean she was just relegated to slobbering on the toy.

“W...what are you…” Cadance trailed off, noticing what held the changeling’s focus. “You’re disgusting,” she murmured.

Unflinching, in spite of her biting words, she allowed the shapeshifter to steadily draw closer to her behind. Seeing the serpent-like tongue flick from the mare’s fanged maw, a tingle of excitement coursed through her. She absolutely adored when Shining lavished her rump with his mouth, so she could only imagine what delights the Queen’s sinful muzzle could deliver. Just as the changeling breathed hotly upon her backside, her opponent abruptly shifted.

“Put yourself to good use, Dear,” Chrysalis purred, shimmying her lower half towards the alicorn’s face. Swinging her hind legs apart, she presented her nethers. “Unless you want to go at it bone dry, you’ll do me this favor…”

Of course, there was bottled lubricant available, although neither mare was inclined to use it. Personally licking and teasing one another would not only serve to slicken their gluttonous holes but potentially allow them to weaken the other. Spying Chrysalis’ nose hovering near her tush, Cadance looked to the changeling’s behind. Shuffling her shoulders and torso forward, muttering darkly to herself, she inched closer to the succulent bug booty.

“Yes, good,” Chrysalis purred, watching the irate alicorn inching closer to her bottom. Without preamble, just as the Princess’ nose pressed against her behind, Cadance reluctantly started lapping at her tail hole. “Don’t be frightened of it, it won’t - Mmmmph!” her jeering came to an abrupt end, as the pony mare french kissed her backside.

Glowering down, Cadance suppressed a shudder of delight as the changeling burrowed her long, vascular tongue into her tush. Thankfully, the thick pucker around her mouth muffled the surprised gasp which escaped her. Besides the physical sensation of being violated by the sinewy appendage, the act of having her face between the wanton Queen’s buns was undeniably arousing.

The earthy, strong musk of the changeling’s ass was all consuming, flooding her sinuses and causing her heart to flutter - the smell, however, was eclipsed by the evil mare’s pucker. Soft as silk and with a velvety texture, she couldn’t have imagined another hole could hold a candle to her own. Shining had written poems about her rump before, yet being faced with the shapeshifter’s behind filled her with self-doubt.

Sensing the Princess’ motions slow, Chrysalis redoubled her efforts. Lipping the thick, fleshy ring of the alicorn’s entrance, her tongue thrashed and swabbed the pony’s interior. She had no idea what had Cadance so distracted - nor did she care - but she was going to take full advantage of the situation. The sooner the inferior mare lost, the quicker she could run off with that delicious little dumpling Shining Armor.

Grunting, forced to focus by the writhing appendage in her rear, Cadance steeled her resolve. Licking around the shapeshifter’s rim, applying a heaping helping of saliva, she spat into the crater-like hole. If Chrysalis was going to play dirty - by Celestia - so would she. Drawing a deep breath, she filled her lungs and closed her eyes.

“Giving up alreeaAAH OH BUCK,” Chrysalis mewled, as the pony’s muzzle burrowed into her well trained backdoor.

It wasn’t that she couldn’t handle an intrusion of that magnitude, but the abruptness of suddenly having a pony’s snout suddenly jammed into your ass would take anyone by surprise. A delighted shiver coursed through her frame, while she fought to compose herself. Furious and aroused, she grit her teeth. Two could play at that little game…

Wincing, pressing her snout deeper into her enemy’s tush, Cadance was subjected to the same attack. Clamping her expertly trained hole around Chrysalis’ face, doing her best to halt the mare’s progress, she was found wanting. Though the changeling’ snout was shorter and a shade more narrow than her husband’s, the lengthy tongue did little to help her. Forcing her own countenance forward, feeling the warm, inviting heat of the bug-horse’s ass, she continued her assault.

Tasting the pony’s interior, Chrysalis wormed her head back and forth. Despite adjusting to the Cadance’s muzzle in her rear, something was amiss. As the strangely sweet, cloying flavors rolled over her taste buds, her razored pupils shrank to pinpricks. Of course, it was love - the blasted pony was the Princess of the infernal element. Through the fog of blissful euphoria, she realized her error and retreated.

Retracting her head, the changeling freed her slickened muzzle. If she’d remained where she was, the influx of amorous pleasure from the Princess would have surely done her in. Licking her lips clean, she magically hefted the nearby sex toy. Levitating the dildo to the pony’s moist and warmed up entrance, she jammed the head inside.

“Mmmmph!” Cadance’s muted cry rang through the room. She was unable to see what was pressing into her, what with her face entombed in the shapeshifter’s backside, though she reasoned it had to be the dong. Pulling back, she took a deep breath and hastily pushed herself up. “You could have given me a warning!” she growled.

“Someone had to be first,” Chrysalis breathed, getting to her hooves. With the flared tip lodged in the mare’s sphincter, the remainder of the substantial length hung limply to the bed. “Well, we may as well get this over with. I’ve got quite a few plans for Shining,” she hummed, lazily wheeling around.

Cadance, seeing the changeling execute an about face, sorcerously lifted the opposite end of the toy in her ass. Feeling the weight of it with her magic didn’t do the thing justice; even though she only had a few inches in her tush, the intrusion was substantial. It almost felt like someone had crammed a hoof in her hole - albeit a somewhat pliable one. Looking down the toy’s length, she swallowed hard.

“Since you seem quite stricken,” Chrysalis laughed, her emerald energy guiding the opposite end of the toy towards her rump, “allow me to show you some initiative!” Bucking back, while simultaneously pressing the head to her pucker, she brazenly impaled herself on the toy.

The sensation of being so full almost caused the changeling to falter - almost. Taking a step backwards, driving yet more of the shaft into herself, she fiercely clenched around the dong. With her hole yielding more resistance than her opponent, as she moved in reverse, inch after sculpted inch was plunged into the alicorn’s backdoor.

As the phallic toy slipping deeper into her rectum, Cadance braced herself and pushed back. The feeling was beyond intense but incomprehensibly pleasurable. After decades of sating her anal yearnings with toys, stallions, and even a few household objects, the act of confronting a whorish bug-horse, while impaled on possibly the largest dildo in production, was astonishingly arousing. Taking a shuddering breath, she took a step backward.

“N - Mmmmn - not bad, P...princess,” the shapeshifter stammered, while the floppy shaft snaked into her colon.

She considered herself fortunate that the alicorn couldn’t see her face because it was twisted in pleasure - still, she was far from defeated. With preternatural control, she seized her anus around the dong and savagely rocked her hips rearward. Her efforts were rewarded, as a hushed whimper escaped her opponent.

In an amazing twist of serendipity, Cadance’s wings fitfully flitted outward; frankly, she’d forgotten all about the feathered appendages, though the reminder gave her an idea. Flipping mightily, she leapt backwards in a tenacious and potentially cataclysmic attack. The quasi-kamikaze onslaught caused practically a foot of the dildo to worm into her guts, leaving her marehood to angrily clench upon itself, yet the impact on her foe was profound.

What remained of Chrysalis’ half of the toy immediately plunged into her depths, filling her in an instant. Her knees buckled, her snatch drooled uncontrollably, and her heart skipped a beat. In the blink of an eye, she’d become a cock sleeve for the oversized marital aid. Were it not for the faint blissful cry of the Princess, kicking her higher functions into high gear, she may have been in an even worse spot - should the alicorn have seized the moment.

Shuffling slightly, feeling the warmth of the pony’s thighs against her own, she bucked back once, then a second and third time, until she was slowly fucking the mare ass-to-ass. With the bulbous midpoint separating the two, knowing she’d effectively bottomed out on her side of the thing, she gyrated her waist. With the alicorn standing motionless, she was left to assume the reckless strike had cost the Princess dearly.

It took Cadance a second to reciprocate, but she quickly regained her composure. Meeting the shapeshifter’s savagery, she gave as good as she got. The trick, she quickly grasped, was to not fixate on just how astoundingly good it felt. If she submitted, welcoming the rapturous onslaught with open hooves, she’d spiral towards climactic failure - as such, she attempted to keep her mind clear.

“Oh Cadance,” Shining’s voice rang out, “you feel absolutely amazing!”

The Princess’ eyes flew open, as her husband’s sensual and profoundly provocative voice drifted to her ears. In spite of her best efforts, her thoughts ran rampant. While part of her knew it was impossible that he was plowing her, her body was stricken by waves of ecstasy. Whipping her head ‘round, she stared daggers at her opposition. The shapeshifting strumpet bore a shit-eating grin, mocking her.

“What? I thought you’d enjoy it!” Chrysalis scoffed, her movements unceasing. “After all, your loving husband told me the same thing…”

Cadance’s horn blazed with turquoise energy. If the harlot could break the rules so could she. With supernatural accuracy, she clamped her magic around the changeling’s teats and savagely twisted. Though it was a bit of a gamble, unknowing if the insect-like equine had a masochistic streak, she was quickly greeted by a loud moan.

“You were saying,” she chuckled, pulling the sensitive buds of flesh.

Growling through the bliss, Chrysalis set her own sorcery to work. Counter-attacking with a teat-based attack of her own, her offensive didn’t end there. Slamming her posterior against the alicorn’s hindquarters, their engorged clits ground against one another. The tactic was risky, to say the least, delivering a comparable amount of pleasure to each of them. She outright refused to lose, so it was a maneuver of last resort.

Viciously retaliating, Cadance pistoned her posterior back harder and faster than ever. Given everything they’d suffered through, teasing one another ceaselessly, it was a race to the finish. She couldn’t be sure of how close the changeling was, but if she had to guess, Chrysalis wouldn’t be able to last much longer.

The shapeshifter’s grunting slowly raised an octave, while their bodies rhythmically smashed against one another. Win or lose, there was no sense in holding back any longer. Employing every salacious weapon in her carnal arsenal, she struggled with her foe. Screwing her eyes shut and setting her jaw, she endured.

Ripples cascaded over their buns and thighs, with every impact from their wild fucking. Gradually, as the minutes ticked by, their movements grew frenzied; gone were the smooth, steady strokes of plowing, replaced by feverish, damn near crazed motions. Their lustful moaning grew louder and louder, until they were practically howling with rapture.

The Queen and Princess leaned forward, steadying themselves for yet another tectonic rearward plunge. As their asses crashed together, they both went rigid. Throwing their heads back, braying in climactic bliss, Chrysalis and Cadance reached their limit. Quivering from head to hoof, their marehoods convulsed and gushed orgasmic nectar to the bed sheets below.

Stumbling, trying and failing to remain upright, the duo crashed to the mattress. Their well used and filled ponuts spasmed around the unyielding length of silicone in their depths, ineffectually trying to milk the cum from the non-functional toy stallionhood. Heaving air into their burning lungs, they fought to recuperate.

“N...not bad, f...for a skank…” Cadance admitted, wearily eyeing her sweat-streaked nemesis.

“You fared - Cough - reasonably well,” Chrysalis reluctantly wheezed.

Between the ecstasy and feast of sensual energy, the changeling was in pretty rough shape. The Princess of love fared little better, her body beset by lightning bolts of pleasure. In a cosmic twist of fate, they’d each peaked at nearly the same instant. Glaring at one another, frustrated with the apparent stalemate, there was only one logical conclusion.

“Another round then? Maybe tomorrow afternoon?” Cadance weakly asserted, wiggling her rear. The experience had been far from unpleasant, as much as she was loath to admit it, so she wouldn’t mind having another swing at her bane.

“Of course. Though next time, I’ll be sure to best you.” Chrysalis muttered, attempting to keep the quiet admiration from her voice. The thought of struggling with the alicorn set her ravenous marehood and backdoor tingling with anticipation, even if she detested the candy colored pony.

“Hmmph,” the Princess snorted, flicking the mane from her face, “we’ll see about that…”