Chapter 1
The first sounds and scents of spring billowed across the Apple family farm. Snow had melted into puddles of cool water, birds sang, flowers bloomed. The land was invigorated with new life.
Most of its residents, too, were invigorated. All of the above, combined with the increasing temperature, meant that the line on the thermometer and the sun weren't the only things rising that morning.
Fluttershy, Rainbow Dash, Rarity, Pinkie, Sunset, and Applejack each awoke at different times, but all with the same problem. An insistent, overpowering warmth in their nethers, alongside a stiff, boiling erection underneath, twitching and bobbing with each step.
It got especially bad for each of them when they left their private rooms in the newly renovated stable they shared, passing the common area and taking their first cantering steps outdoors on the way to squeeze into the farmhouse for breakfast.
Rainbow Dash was the last to emerge, shaking on her hooves as the signals of the season cranked up her new body's instincts to 11. The others, too, had stopped in their tracks, fidgeting indecisively on the grass.
Rainbow peeked under their barrels, spying that her friends were all suffering from the same issue, and groaned. "Okay, I've never been this horny before in my god damn life, and it looks like I'm not the only one. What the fuck is going on?" she asked.
Applejack, who was tugging at the edge of her flannel shirt, answered. "We're in heat. Happens to mares every spring."
Sunset nodded, biting her lip. She reached behind herself to pat at her jet black horse body, matching her jacket. "It was never this bad back home, though. Probably because we're also in rut."
Rarity couldn't hold back a ladylike moan, her face flushed as her gold blonde coated flanks clenched in need, drawing the eye away from the stylish handmade saddle on her back and the huge, unsheathed package bobbing beneath her. "It was already bad enough that I can't reach back there to tend to myself, but this is..."
Pinkie pranced anxiously in place, her breasts bouncing beneath her shirt as her tail flagged high. Her own erect horsecock was dappled with cream-colored spots just like her tan coat. "Tell me about it, sister! I was already having trouble ignoring my pussy and penis as they were, but if they're gonna be this demanding, I don't think I'll be able to calm down until I party hard."
Fluttershy trotted anxiously in a circle, groping at her chest as her cunt leaked fragrant fluid onto the grass. "Oooh my. I hate to ask, but, um, could I possibly ask one of you to mount me like an animal and rut me stupid? I haven't been able to masturbate either, and I really need it." Evidently, she couldn't wait anymore, presenting her grey, equine ass to the group.
At the sight of her oldest friend in such desperation, Rainbow's dick throbbed beneath her something fierce, and she rapidly, automatically moved in to help, unable to deny Fluttershy or herself. However, Applejack had the same idea, and they bumped into eachother, Rainbow's white lower half jostling into Applejack's rich brown. The contact made both their desires rise even higher.
"Sorry, sugarcube," Applejack apologized, stepping back. Her eyes roved over the rest of her friends. "I'll start with another partner, assuming y'all are as raring to breed as I am."
"Please," Sunset begged, joining Fluttershy in baring her aching cunt, its thick lips glistening in the air. "I know some of you haven't totally forgiven me for everything, yet, so let me make it up to you with this. Feel free to cum as much as you want inside me, everyone. I'll take your foals first, Applejack."
"Well, I'll accept that kind offer, Sunset," she confirmed, unbuttoning her shirt as her enormous, three-foot bitchbreaker tensed and oozed in anticipation of claiming the former bully.
With them paired up, Rainbow was free to resume approaching Fluttershy. Moaning, she reared up and gripped Fluttershy's sides with her forelegs, prompting an 'eep' from Fluttershy as Rainbow shimmied along her body, their hearts pounding. "Mmm, I'm really digging your new assertiveness, Shy. Must be the cock."
The remaining two girls fell into eachother's seductive orbit, Rarity taking the submissive position to start. "Goodness, are we really doing this?" she uttered, hesitating for a few seconds before lowering herself down onto the elbows of her forelegs, making her pussy easier to access. She was even wetter than Fluttershy, and her clit was winking madly in and out of view.
"Yep, and it's about time!" Pinkie confirmed, approaching Rarity from behind. "I'd been meaning to put together an orgy for a while now, so I could give you guys lots and lots of love. You're just first, Rares!"
They'd never crossed the line from friends into friends with benefits before, fearing their relationships might not be the same afterwards, but the primal desires of their bodies shattered the barriers keeping them apart. It all happened at once, with Rainbow, Applejack, and Pinkie each penetrating their friends at the same time, six simultaneous cries of bliss ringing out as wide cockheads pushed inside, quickly followed by sensitive medial rings.
While having their searing depths suddenly stretched out by the largest insertions they'd ever taken in their lives certainly felt incredible for Fluttershy, Sunset, and Rarity, bliss shooting up their spines, it was even more intense for the others. None present had ever fucked someone with their penis before, and the pulsing sensations of having them embraced on all sides by warm flesh rocked their worldview.
"Holy shit," uttered Rainbow Dash, unable to control her body as she thrust in and out of Fluttershy, who exhaled breathily with satisfaction beneath her, continuing to squeeze her breasts through her clothes. "No wonder boys are thinking about sex all the time. This feels incredible, Fluttershy."
"Y-Yes," Fluttershy confirmed, savoring the connection between them as her body melted beneath Rainbow's.
Meanwhile, Pinkie was smiling blissfully as she rode Rarity, indulging in the joy of sex from a new perspective. "Wowwie, this feels spectacular! I'm totally going to get addicted to this, I just know it. Maybe even - ahn - more than cake."
"M-Me too, darling," Rarity echoed, arching her back. "Your shaft is so unbelievably thick, Pinkie, I feel like I could lose my mind." Wanting to make things more intimate, Rarity then twisted her upper half around, pulled Pinkie in, and start passionately making out with her.
Applejack, however, wasn't having sex with Sunset; she was rutting her. "That's right, Sunset, you're my mare now," she declared, her whole body already bucking and tensing with coiled energy atop Sunset's. Between motions, she tugged off Sunset's clothes. Sunset didn't resist, Applejack tossing one garment at a time onto the dirt until her perky orange tits were bared. "A-And I think I'm already about to blow."
"D-Don't hold back!" Sunset insisted, grinding her frame up into Applejack's as her pupils widened from sensory overload. Her hungry womb was absolutely begging for it. "Use me however you see fit, pump me full of your stud jizz!"
This goading proved too much for Applejack in her inexperienced, pent-up state, and she bottomed out inside Sunset with a shout, her climax hitting like a truck as thick gouts of semen erupted through her dick. White creeping into her vision, Applejack grit her teeth as she rode out her ejaculation along with Sunset, who, upon feeling her voracious snatch getting painted, came herself, her tunnel wildly wringing out as much of Applejack's essence as it could.
As those two were overcome by orgasmic pleasure, Rainbow was getting very close herself. "T-Tell me what you want!" Rainbow cried out to Fluttershy as she pistoned more forcefully into her, the heavy sound of their bodies meeting echoing through the farm and adding to the symphony of raw sex.
"I want your cuuuum," Fluttershy moaned, her tail lashing up against Rainbow's fat nuts as she went deeper and deeper. "Stuff me with your seeeed, Dashie!"
Now it was Rainbow's turn to erupt, her turgid meatstick pulsing with lascivious pressure as she fulfilled her friend's desires. Gasping for air more so than after a dozen races, Rainbow lost all control over her muscular centaur self, surrendering completely to the whims of her burning need and pressing her whole weight atop Fluttershy. "It's all for yoooou."
As Fluttershy shook with a climax of her own, waves of electric fire churning in her core, Rarity pulled her lips from Pinkie's, whining in need. "It's r-rude to keep a lady waiting, Pinkie Pie. I demand you give me a creampie this instant, my pussy can't take being denied for much longer."
Pinkie could only groan and nod as she, too, tipped over the edge. "It's c-coming out. I can't hold in my baby batter!"
Hooves scraping the dirt as her flaring head scraped Rarity's pussy, Pinkie let loose, unleashing pump after pump of potent spooge into Rarity. Rarity screamed as she crested her own peak, her whole body spasming in ecstasy as Pinkie utterly claimed her.
Once their orgasms faded, Rainbow, Applejack, and Pinkie slowly, reluctantly, pulled out and stood on four shaky legs, their dicks still rock-hard, now glistening in the sun with juices. None of them had gotten soft, or looked like they would anytime soon, with Fluttershy, Sunset, and Rarity's lengths also eagerly twitching in anticipation as they collected themselves, taking a momentary reprieve as their collective haze of afterglow gave way to another wellspring of needy desire.
Everyone besides Applejack and Sunset quickly disrobed, revealing stiff nipples and bouncy busts while ensuring more skin-to-skin contact. Rainbow's boobs were the smallest, but she made up for it with the largest horsecock. Not by much, though, as all the girls packed erections over two and a half feet long. Their clits, too, continued to wink in readiness as their pussies kept oozing natural lubricant. The only pieces of clothing left on were Applejack's hat, which shaded her freckled cleavage, and Rarity's saddle.
Words didn't need to be exchanged; their desires made their movements and musky pheromones do the talking for them. The six girls switched positions, with Applejack, Rainbow, and Pinkie lifting their tails and sending lewd looks over their shoulders.
The others, who had yet to get their dicks wet, each picked someone different from their prior fuckbuddy. Rarity licked her lips and cupped her chin as she drank in Applejack's toned curves, precum dripping from her golden glans. As she closed the distance, she declared "I'm very much looking forward to showing you what I can do, Applejack, dear."
"Taking the initiative in getting down and dirty for once?" Applejack replied with a smirk. "I can take whatever y'all can give."
Meanwhile, Fluttershy trotted up to Pinkie as if pulled by her own steaming dick like a dowsing rod towards water. "Mate with me, Pinkie," she said, in a tone which waffled between a hesitant question and an absolute order.
"Go for it!" Pinkie exclaimed, wiggling her massive, dappled ass, clearing any doubt.
Lastly, Sunset gravitated towards Rainbow, sniffing deeply. "Unf, your pussy smells so good, Rainbow. It's okay if I violate you, right?"
Rainbow dropped to her knees and posed with her hands behind her head. "Like what you see, do you? I suppose you can, but that cock better be as feisty as mine is!"
The three high school mares mounted and penetrated their friends one after another, a fresh set of sounds, spectacles, and sensations rolling through them. Sunset's night-black body smothered Rainbow's milky white, their eyes lighting up with passion. Sunset savored each pass like divine ambrosia, bathing in the magic of her horsecock, wrapped in tightening, athletic cunt. Fluttershy let go of all her inhibitions, pounding Pinkie into the ground with her full strength from the start as she unshackled her every animalistic urge, the hormones from her balls replacing 'gentle' and 'demure' with 'aggressive' and 'unapologetic'. Pinkie giggled from the rush, happy to be used. And Rarity growled, her big breasts dancing against Applejack's upper back as she fucked and fucked and fucked like there was no tomorrow with her newly popped cherry. Applejack watched the others, enjoying the show as Rarity drove her wild.
"You can be rougher, Sunset! Give me all you've got with that super big dick of yours!" Rainbow cried, her tongue lolling out as she panted.
"Are you sure, Dash? I don't want to break you," Sunset noted, barely restraining her lust as her voluptuous chest heaved with deep breaths.
"I'm sure!" Rainbow insisted, planting her forearms onto the ground too, completely submitting.
Snorting, Sunset stopped holding back, her overfull balls slapping against Rainbow's flashing clit as she jackhammered without care for Rainbow's continued health or sanity. Both their releases were fast approaching, moaning in unison as the fire and pressure built towards the point of no return, whereupon Rainbow would likely be knocked up with Sunset's baby.
Simultaneously, the others had been interlocking their bodies in a sea of pleasure. "Do you suppose - oh heavens - that your siblings are watching us right now?" Rarity asked. "Imagine what they must be thinking as I plow you into next week!"
Applejack shuddered, her pussy clenching voraciously around Rarity's length in response. "F-Fuck, they'll think their sister is little more'n a bitch in heat. And they'd be right!"
"Exactly so," Rarity uttered, groaning as her motions grew erratic. "Shit, this feeling is—"
"Great? Almost as great you're making me feel, Rares," Applejack said, her hat nearly flying off from how hard Rarity was going. "I don't care who sees, I'm yours."
However, as forcefully as Rarity and Sunset were moving, Fluttershy had them both beat. Each of her long, mythical strokes rattled Pinkie like a battering ram, the to the point where she was going stupid with arousal. Her expression could only be called an ahegao, and Fluttershy observed this with pride.
"Gaaah, I can't bring myself to care about anything else except your dick hitting my cervix, Fluttershy!" Pinkie admitted, basking in the feeling of fullness, of her friend's commanding heft pinning her down. "I'm never asking for a facial agaaaain."
"That's a good girl," Fluttershy purred, moving like she'd had a penis her whole life. "You don't get to pull away, not until I've nutted inside you."
"Yes, yes, yes, I'm gonna have a bun in my oveeeen!" Pinkie howled.
In rapid succession, they all came again. Sunset's eyes zoned out as her mind went blank, her entire being giving way to the singular purpose of emptying pints of seed into Rainbow Dash, whose limbs twitched and tail lashed as her own body was overcome with supreme fulfilment. Fluttershy practically whinnied as her balls churned out a volcanic load for Pinkie's eager womb, her cock pulsing with just as much molten energy. Pinkie's hair wigged out as she was consumed by the sparks shooting through her vivacious nerves, presenting her boobs to the air as her body was locked in lewd spasms. And Rarity let out a shaky sigh as she ravished Applejack's most intimate parts with lots and lots of her liquid love, Applejack herself seeing not just stars, but a whole galaxy.
However, upon retreating with a trio of squelches, the six centaurs immediately realized there had to be a round three. And it wouldn't stop there.
They all needed more. Lots more.
In the end, the girls weren't satisfied until each of them had both fucked and been fucked by everyone else. Sunset, Rainbow, Pinkie, Rarity, Fluttershy, and Applejack all returned to the stable to cuddle side by side on some hay piles, their balls emptied after five copious ejaculations and their wombs stuffed to bursting, mixed cum dribbling slowly out between their lower lips.
After repeating this process every day for the rest of the week, their uncontrollable urges became bearable, though they all still mounted eachother regularly. Now that the ice had been broken, they formed a proper polycule herd.
It became clear that the six teenaged centaurs were pregnant after a little while. After they gave birth to cute fillies like themselves a year later, they repeated the process with another series of spring orgies, and would continue to do so every year thereafter, until the farm was home to a hardworking horsegirl family too huge to keep secret. Still, they all lived happily, and hornily, ever after.