Rarity's Naughty Cave Adventure

by Clopfic Appreciator

Rating: mature
Tags: Anthro, My Little Pony: Friendship is Magic, Diamond Dogs, Porn, Rarity, Sex
Length: 4452

Visiting the Diamond Dog caves, Rarity has a close personal encounter with an especially hunky Dog.

Rarity has established a friendly relationship with the local Diamond Dogs, both for the purposes of trade and for more personal reasons. On her latest trading trip, she gets to meet a big, friendly Diamond Dog. How big? Very. How friendly? Extremely.

Contains: interspecies sex, bossy Rarity, slobbery tongue action, big canine cock, naughty uses of magic, knotting, cervical penetration, mild cumflation, and a very satisfied, overfucked unicorn.

Cover art cropped from Zwitterkitsune's extremely NSFW artwork on their FA gallery: https://www.furaffinity.net slash view slash 44447744

Published 2023-01-30 01:40:01 UTC
Last updated 2023-01-30 01:40:01 UTC

It's Spelled 'Knotty'

“Six bolts of first-grade moleskin cloth?” Rarity said, in a calculatedly shocked tone. “On top of the cider and the foodstuffs, not to mention the new pickaxes? Out of the question! Why, I’m making precious little profit as is, with the imports from Griffonstone driving down gem prices already. You are abusing my generosity with such outrageous demands!”

The russet-furred Diamond Dog bitch sitting across the stone block that served as the negotiation table chuckled. “Dog thought pony liked being abused,” she said with an impudent grin.

“Why, I never!” Rarity replied, wondering why the boss Dog was driving such a hard bargain. After the initial kidnapping debacle was over, and Rover and his cronies had been ousted from power in the warren, Rarity had managed to establish a trading relationship with the Diamond Dogs: they mined gems for her, and she offered them pony goods in return. There was a lot of haggling and arguing involved, but she almost never had to resort to whining any more. “If you insult me one more time, Ruby, I am going to have to reconsider this entire trade.”

The Dog’s grin just broadened. “Ruby thinks pony should see something before pony leaves. Ruby thinks pony will like it.” She raised her paw to her lips and gave a piercing whistle.

Before Rarity could ask any questions, another Dog entered the trade cave. Rarity’s eyes widened as he – and he definitely was a he – lumbered into the gem-lit room from the low-arched tunnel and straightened up to his full height. He was possibly the biggest Dog Rarity had seen, in every sense. The cave-dwelling canines wore collars and vests, scarfs and tool belts and pouches, but never pants, and the sight of his massive balls and thick sheath irresistibly drew Rarity’s gaze. She felt her face flush and knew that the boss Dog had her.

“Pony does like?” Ruby asked, her smug tone making it clear she knew the answer to her question was a resounding Yes.

Besides trading, Rarity’s visits to the caves had a second, personal reason. Behind her carefully cultivated refined façade, the elegant white unicorn was as promiscuous as they come. Her sex life was vigorous and varied, with plenty of ponies of both sexes – though more stallions than mares – in her circle of intimate friends. But there were some itches her pony partners couldn’t scratch, and that’s where the Dogs came in.

Rarity got a huge kick out of being roughly fucked by the crude, coarse Diamond Dogs, their knotted cocks stretching her pony pussy out as they pounded her hindquarters, slobbering and grunting and whining. The taboo nature of interspecies sex, and the contrast between the Dogs and her usual partners, gave her a thrill like nothing else. And the best part was that there was no chance of pregnancy whatsoever, so she could dispense with condoms and contraceptive charms, and let the pack cum inside her, again and again, until her flat belly was bulging with hot, gooey Dog semen.

“Y-yes, I do like,” Rarity admitted, reluctantly tearing her eyes away from the new Dog and looking back at Ruby. “On a second thought, perhaps I can do six bolts after all. But only if I’m satisfied with this fellow’s performance, mind you!” It would cut her profit margin very thin, but she couldn’t let this opportunity go by. Bits, after all, were just bits!

“Pony does not have to worry,” Ruby said, turning around and pointing a thick, clawed finger at the big male. “Runt, remember what Ruby told you. Do everything pony wants, or else! Now, pony want privacy, yes?” Chuckling, she scampered around the hulking Dog, and vanished into the tunnel.

Rarity gave the big Dog a good long look, from head to toes. He was indeed very big, with the typically overdeveloped upper body that all the mining and digging gave to the Dog males, but better proportioned than most. He had short, smooth, dark brown fur, lighter along his belly and mottled on his face and shoulders. His face was less jowly than some Dogs’, with big triangular ears and maroon eyes that looked back at her with more intelligence than most. His arms were long and thick, his legs short but muscular, and the knobbed end of his tail almost mace-like. He wore only a broad tool belt slung across his body, with not even the simplest collar around his thick neck, suggesting poverty or low pack status… which tended to be the same thing among Diamond Dogs.

“You’re… Runt?” she asked, almost giggling at the incongruity of the name. This was the least runty Diamond Dog she had ever seen!

“Yes. Dog was the last one in a big litter,” he said, his voice deep and gravelly. “Used to be small and weedy as a pup. Then had a growth spurt… but the name stuck. Dog used to it.” He gave a little shrug, as if to show it was all the same for him, but his ears had drooped.

“Well, I for one think you are a very big and very handsome Dog,” Rarity said, giving him a sultry smile as her gaze roamed across his body, returning again and again to his huge package. Those balls would have been big on a draft stallion, let alone a Diamond Dog. And that sheath! The promise of it was making her drench her panties. Could he smell her excitement? Rarity saw his nostrils twitch and felt another flash of heat through her loins. He could! Even if he didn’t quite understand what he was smelling yet, he could. It made her feel wonderfully vulnerable and naughty at the same time. “My name is Rarity. It’s a pleasure to meet you, Runt.”

Now it was Runt’s turn to stare. Even in her caving gear, Rarity was a looker. She’d long ago resigned to the Dogs not understanding any but the crudest aspects of pony beauty and had thus tailored her overalls to emphasize her hourglass figure, with sizeable bust and generously curving hips. She smiled and shifted her pose a little, thrusting her chest out more, and was rewarded by Runt’s eyes focusing there.

“Pony… Rarity is a very nice-looking pony, too,” he said. “Nicest one Runt has ever seen.”

This piqued Rarity’s curiosity. “Oh? And have you seen many ponies?” she asked, putting her arms akimbo and tilting her hips slightly, drawing his eyes down. My goodness, this is an easy one!

“A few. Runt… has been up on the surface a few times, at night. Heard a lot about ponies, so got curious about them. Only saw a couple of lady ponies, from afar. They were pretty. And seemed nice, nicer than the Dog girls Runt knows.” His ears flipped back as he looked back up at Rarity’s face. “They think Runt’s too big.”

“Oh, you poor thing,” Rarity cooed, both amused and excited by Runt’s admission of interest in ponies, and by the implications of him being ‘too big’. “Would you like to learn more about lady ponies?” He nodded eagerly, and Rarity had to stifle a laugh. “I’m going to give you a little lesson, then. Now, just stay there and watch,” she told him and started unbuttoning her overalls.

Rarity tried to make her undressing into a bit of a show for Runt, even though she was limited by her wardrobe of a jeweled hard hat, overalls, safety boots, and a cheap and practical set of underwear. There was always the risk of any lingerie getting ripped up by excited Dogs, but this time she wished she’d worn something risqué, with lots of straps and black lace. Even so, Runt seemed very pleased with what he was seeing, with the pointed red-pink tip of his dick peeking out of his sheath. The sight of it made Rarity’s mouth water, and she considered the possibility of going down on him… No, as tempting as it looked and smelled, with a clear bead of precum already showing at the tip, that dick was going into her cunny first!

Now fully nude, Rarity did a little twirl, to ensure he got a good look of her from every side, before she sauntered over to Runt. “Let me help you with this,” she said, putting a hand on the tool belt across his chest. “Bow down, you’re too tall for me.”

Runt crouched down, his gaze drawn to Rarity’s full breasts as she lifted the leather belt over his head. Suddenly, she felt one big paw grope her thigh. She didn’t hesitate for an instant: dropping the belt to the floor, she gave him a firm smack on the nose with an open hand. “No! Bad Dog!” she said firmly. “You’ll do everything I tell you to do, Runt, but nothing more. Take that paw off my leg, now!”

The massive Dog gave her an absurdly cute puppy-dog look that made Rarity’s heart and loins melt alike. She almost told him to go ahead and take her right then, but she resisted the urge. It would be much more fun to play the stern mistress and make the huge hunk of a male obey her, until the moment came to let him loose to fuck her silly. “Runt, you will obey me,” she ordered, looking him in the eye and giving him her best imitation of Fluttershy’s Stare.

That did it. The big Dog pulled his paw back and crouched down. “Runt is sorry. Will do what Rarity says,” he said, and now there was a bit of a whine to his voice, too.

“Good boy,” Rarity said, savoring the thrill of mastery. “Now… you can start learning about lady ponies… from the hooves up.” She took a step back and offered one well-polished hoof forward.

Runt nodded and dropped down on all fours, giving first the one, then the other hoof a lick. He had a big tongue, and Rarity shivered at the thought of what he could do to her with it. The hotness of it contrasted wonderfully with the coldness of his nose, as Rarity slowly guided him up her legs and thighs, every touch making her more excited.

Before he reached her crotch, Rarity put a hand on his head. “Stop,” she ordered. Runt’s eyes crossed as he watched her dip two fingers into the wet folds of her pussy, then rub the juices on his nose. The effect was immediate: his cock, which had still been halfway in his sheath surged out, swelling to its full size and hardness. A squirt of precum shot out, landing on Rarity’s leg and making her smile. Oh, he’s excitable!

She dipped her fingers back into her dripping sex and traced a glistening path of wetness across her trimmed bush, up to her navel and across her belly, to her breasts, and finally along her neck and jawline, to her lips. “Follow my taste,” she ordered Runt.

The Dog obeyed eagerly, her big slobbery tongue feeling incredible as it slid across her velvety coat. Her pale pink nipples grew hard as little diamonds as he poked his cold, wet nose at them. Rarity gasped as he took his breasts into his mouth, one by one. She was proud of her large, round tits, and never had she had a partner who could cover the entirety of each full breast with their mouth! She let Runt linger on her chest longer than she had planned, luxuriating in the big Dog’s worship of her boobs, but as lovely as it felt, she had more in mind. So, she drove her fingers into her pussy for the third time and painted her lips with her juices. Celestia’s garters, I’m getting so wet! “Up here, Runt,” she said, her voice quavering.

He straightened a bit, meeting her muzzle with his own and giving her face a hearty lick. Runt’s eyes widened in surprise as Rarity grabbed his head and tilted it a bit, then slipped her tongue into his mouth in the very first Prench kiss of his life. As he responded with his own tongue, Rarity reached – finally! – for his cock. The huge rod felt burning hot under her touch, its smooth length slick with the precum that was now constantly leaking from its tip. She gave it a squeeze and felt Runt stiffen as she slid her hand down to his sheath, feeling the furry flesh spread and slide back to let the Dog’s fist-sized, veiny knot slip out.

That was the moment Rarity decided she’d had enough foreplay. “Mwah-hah… Let me… let me just get to a comfortable position,” she panted as she broke their kiss and stepped back, her legs feeling a bit unsteady under her.

Luckily, the cave had plenty of pillows Rarity had provided for her previous sessions with Diamond Dogs. In her regular mood, she would have wrinkled her nose at the stuffy, musty smells of cave dirt, pony sweat and Dog spunk coming from the indifferently cleaned pillows, but right now she couldn’t have cared less about that. She gathered a nice pile, then got down on it and raised her rump, her tail flagging and revealing her pony pucker and dripping wet cunny to Runt.

“You’ve already had a taste of me,” she said, looking over her shoulder. “Now, come and try it straight from the source!”

The Dog leaped into action, shoving his muzzle into her crotch, and giving her sopping sex a long, slow lick that made Rarity’s eyes roll back in her head. She no longer had to guide him, just hold on and enjoy herself as Runt ate her out with gusto. From her pussy, he moved up to lick and nuzzle her ass, then headed back down again to tickling her erect clit with the forked tip of his tongue, sending shivers of sensual pleasure through her loins. He was as unpredictable as he was unrelenting, and it didn’t take long for Rarity’s pleasure to soar into a real gusher of an orgasm that wetted his face with her marecum.

While he pulled back, looking satisfied as he licked her juices off his chops, Rarity slowly caught her breath. Just that one orgasm felt like it had been worth everything the boss bitch had demanded, never mind the gems! And there was still that huge, hot, lovely Dog dick to try out…

“Runt, listen carefully,” she said, watching his ears perk up. “I want you to fuck me. I want you to plough my pony pussy hard and make me cum until I see stars. Can you do that?” He nodded, eyes wide, and Rarity laughed giddily. “Good boy, Runt. Now, take me!”

He was on top of her in an instant, supporting himself with those big arms and putting just enough weight on Rarity’s back to make her feel his sheer size. His hips twitched, the hot pole of his cock poking at her thighs and crotch, but not hitting the right spot. Looking back, Rarity lit her horn, and grabbed Runt’s dick in her magical grasp. The sudden glow and unfamiliar sensation made the Dog yelp, and try to pull back, but she tightened her hold, pinning him in place.

“Don’t worry, Runt. I’m not going to hurt you, I’m helping you,” she said in a voice that she hoped was gentle and calming, rather than cock-crazed, as she aimed the canine cock to her entrance and gave him a tug. Runt responded by thrusting, and her breath hitched as she was suddenly speared by his tremendous length.

While she would have vehemently denied being a size queen, Rarity did have a thing for big dicks; “Bigger isn’t necessarily better, but it IS bigger” was her unspoken motto. Even so, she was glad she was so wet and relaxed by her earlier orgasm: Runt felt even bigger inside her than she’d hoped!

“Ahhh… have you done this before?” she asked as he cautiously withdrew, and then slowly thrust back into her.

“N-no,” Runt said, his gruff voice full of wonder. “Dog girls… uh… they think Runt’s too big. They… they ask Runt to lick them, then use paws to get Dog off… or have Runt hump their thighs… Then there was time Chalkie ate too much funny mushrooms, and… and she took Dog in her mouth…”

“Well, darling, those – ah! – those bitches don’t know what – oh! – they’re missing,” she said, loving the idea that she was this big, hunky Dog’s first proper fuck. “Now do – ah! Do go on, I’m not – uhh! – not going to break!”

Runt’s reply was a harder thrust that made Rarity squeal with pleasure. Picking up speed, he plunged his cock again and again into her, deeper and deeper, until he was bottoming out in Rarity’s cunt. The hot bulb of his knot mashed into her pussy lips and her defenseless clitoris with each rapid thrust, while the pointed tip of his canine cock knocked on her the entrance of her womb. It hurt at first, but the pain quickly melded into the pleasure of being taken, hard and fast, by this huge brute of a Dog, his cock stretching her out and making her moan with mounting bliss.

“Ah-ah-hahh! Runt, p-please, ahh, angle down, yes, like that, yessss!” she babbled as his dick now slid over her G-spot with his thrusts, quickly building up her pleasure until she indeed saw stars, as her second climax exploded through her body. She let out a choked wail of joy as her eyes watered and her horn threw off sparks as waves of pleasure rocked her… and the whole time, Runt kept humping her fast and hard.

He was getting quite loud now, grunting and whining as he hammered her pussy. The big Dog seemed tireless, but Rarity always had a keen ear for her partners, and over several excursions she had grown familiar with the sounds the Dogs made during mating. He desperately wanted to cum, she realized, but couldn’t quite get there, not with his knot grinding into her cunt but unable to enter. Several choices flashed through Rarity’s head – using her mouth, her hands, her tits or her magic to give him the release he craved – before an especially daring and naughty idea seized her. It would leave her sore for days, if not longer… but right now, she couldn’t care less about the consequences.

“Runt! S-stop, do you hear me? Ah! I n-need to be, ah, able to concentrate!” she cried. The big Dog slowed down his thrusts, then stopped, half of his dick still lodged in Rarity’s trembling cunny. “Now don’t be alarmed, Runt. I’m going to do some magic,” she said. “J-just be still… I want to get this right...”

Gathering her focus, Rarity brought a very particular spell to her mind and started casting. Her horn glimmered, then glowed brighter and brighter, making Runt whine nervously. Feeling the spell pattern form properly, Rarity turned her mind’s eye inward, and sent a purple wave of magic down into her abdomen. Runt let out a scared yelp as he felt magic flowing over his dick, as the spell spread across Rarity’s marehood, from her pussy lips to her womb, and soaked into her body.

Rarity drew a shaky breath; she had never been much of a mage, which was one of the reasons she cast this particular spell only very rarely. Called Electrum’s Elasticity Enchantment, it had been crafted centuries ago to help with foaling, but generations of unicorn ladies had used it for naughty purposes from nearly the day it was invented.

“R-Runt, darling,” she said, her voice trembling as she looked up at the massive, panting Dog looming over her. “That spell… made me more flexible. I… I can take your knot now. S-so… go ahead and fuck me hard!”

He gave her an incredulous look and saw the sincerity in her eyes. Ears perking up, his face split by a sudden enormous grin, Runt pulled back until only the very tip of his dick was still inside Rarity and rammed his cock back in with all his tremendous strength, making her belly bulge out.

The fierce thrust drove breath out of Rarity’s lungs, along with every thought in her head but one: Oh, sun and moon, I’m so fucking FULL!!! Even with her lady parts made magically stretchy, Runt’s canine cock was too big to enter her fully with just one thrust. But with each slam of his hips into Rarity, the pointed tip of his dick wedged her suddenly yielding cervix open a little more, just as her pussy lips stretched further and further around his massive knot. Her poor helpless clit was getting absolutely steamrolled by Runt's thrusts, making her whole body twitch and tremble in time with the hot, hard bulge grinding into her sensitive pleasure bud.

With the next thrust, her body’s resistance broke: Runt knotted fully in Rarity, streatching her pussy lips obscenely wide before they snapped closed around the stem of his dick, making her feel the fullest since that memorable Ponytones afterparty when drunk Fluttershy had fisted her to a mind-bending orgasm. At the same time, the tip of his surged through her cervix and penetrated deep into her womb, sending spasms of pleasurable pain through her body as her most intimate sanctum was invaded by Runt’s cock. The sheer naughtiness of this sexual defilement triggered Rarity's third climax. It blasted through her, the entirety of her marehood squeezing and milking the Dog’s hot shaft that filled her up completely. She wept tears of pain and joy as she bit down on a pillow, muffling her screams of pleasure and keeping the entire Dog warren from hearing how much she loved being so utterly, completely taken by Runt.

The big Dog was at the edge of cumming, too; with Rarity’s body clinging to his entire length, he was drilling her womb and cunny with ferociously hard half-inch thrusts, his clenched scrotum hammering her swollen, throbbing clit like a wrecking ball that was pushing her mind closer and closer to shutting down from sheer animalistic pleasure.

With a grunt and a howl, and a final thrust that drove him deeper into Rarity’s core than any of her lovers had ever been, he came in her. A huge load of cum surged forth from those massive balls pressing against Rarity’s overstimulated clit, and poured right into her womb in a scalding flood of Diamond Dog jizz, making her abdomen swell rapidly, until she looked like she was several months pregnant.

Even with the elasticity enchantment, Rarity’s body couldn’t stretch fast enough to take it all, and a whole torrent of semen poured out from her ballooning womb, through her winking cervix and down her spasming tunnel, to leak out from around his knot in hot spurts. Feeling the flood of Runt’s thick cum fill her, Rarity came for the fourth and final time, her brain turning into happy mush as unbearable pleasure blasted every last sapient thought from her mind. With her eyes rolling back in her head, she went out like a blown candle.

When she woke up, Rarity didn’t quite remember where she was or what had happened. She stared at the dimly lit, gem-studded rock ceiling, feeling exhausted yet elated, her nethers pleasantly sore, and acutely aware of deeper parts of her body she didn’t usually even feel…

A big, canine face filled her field of vision, and a huge paw took her hand, giving it a gentle squeeze. “Rarity? Is pony all right?” Runt asked, as the memory of what had happened surfaced in Rarity’s mind.

She groaned and squeezed her eyes closed; she had really given into her lusts this time! Sure, it had felt wonderful – the absolute best sex she’d had in many moons, in fact – but she could already tell she’d be feeling the effects of taking a knot the size of both her clenched fists, and getting her cervix penetrated and her womb fucked, for a good long while. That damn spell… never again, she thought. Until the next time, I guess.

“Yes, darling,” she said, opening her eyes and looking at Runt fully. “I’m just a little tired, that’s all. You were marvellous, though.”

The big Dog’s concerned expression melted into a dopey look of happiness that made Rarity’s heart leap. “Runt never had such good time before,” he said. “Dog will never forget Rarity.”

Rarity tried to look offended; judging by Runt’s amused expression, she had failed. Never mind. “I would hope not! I very much intend to be coming back to see you again,” she said. “Though not in a while, probably. Meanwhile… I think you’re far too nice a Dog to be called Runt. We should come up with a better name for you, darling.”

Runt’s eyes widened and his ears perked up. “Pony – Rarity means that?”

“I do! In fact, I can bring you a very pretty collar next time I visit, with a silver plate that has your name on it,” Rarity said. The big fellow certainly deserved something nice for his stellar performance. "Now... do you have anything in mind?"

"Umm... Diamond, maybe?" he said. "If... if Rarity is okay with that?"

Rarity lifted her head from the pillow and looked down her body, to her hips where her cutie marks – three blue diamonds – were prominently blazoned.

"Very flattering," she said, "but perhaps something else is more appropriate. It's more of a female name anyway, don't you think?" She thought for a moment. "How does 'Max" sound to you? It's Old Unicornish, and means 'big'. I think it would suit you!"

The Dog's ears perked. "Dog likes that. Much nicer than Runt!"

"Well then, Max it shall be!" Rarity said and gave him a dazzling smile. “Now, if you’d just do one teensy-weensy little thing for me… I’m afraid you’ve left quite a mess in me,” she continued, gesturing to her still gaping pussy that was oozing cum onto the pillows. “Be a dear and clean me up, will you?”

The newly named Max looked at her, then nodded eagerly. As the Dog moved between her legs and started lapping up his own jizz from her cum-filled cunny, Rarity laid her head back down again and gave a happy sigh. Those Diamond Dog bitches really did not know what they were missing!

Author's Note

Nowhere near enough hot Diamond Dog on Rarity action on this site!
Especially of the consensual sort. :duck: