Ride Below the Crupper

Mac steadily lumbered through town, sluggishly making his way from one of his many stops to the other, though his thoughts were far from the errands he’d neglected from the day prior. The excitement of spontaneously making wild, passionate love to his little sister had died, replaced by a deep-seated, existential conundrum that had occupied him throughout the night and into the morning. He loved and cherished Bloom with all his heart, but his fling with her had made him question how he cherished her.

He’d watched her grow up, guided through her childhood, and seen her blossom into an attractive, lovely young mare. While he’d never thought he’d look at her as anything more than a sibling, her confession to him, paired with the fact that there was an all too real chance he’d put a bun in her oven, had resonated with some dormant or possibly suppressed part of his mind. He’d never dreamed of viewing her as a lover and potential mate, yet he couldn't stop thinking about elevating their relationship to a romantic level.

“Watch it,” a stallion grunted, narrowly avoiding the ponderous titan.

Grunting his apologies, Mac entered the town hall and moved towards the receptionist’s desk. Regardless of how he dealt with the pickle he’d put himself in, there were things he needed to do. He’d already secured an order of feed for the chickens and pigs, he’d pay his bills shortly, and his final stop of the day would be to pick up a few groceries, yet knowing he’d be seeing Bloom within a few hours and, if his intuition was anything to go off of, he’d have to address their activities from the night before.

He knew full well that she wouldn’t cause him any trouble, outside of possibly asking for a repeat performance of their amorous evening, and that she’d more than likely respect his wishes to refrain from any such taboo fraternizing in the future - no, his real concern was how he was going to react to talking with her again. No matter how things played out, a part of him was tempted to indulge her incestuous fantasies.

Aside from his personal angst about the taboo development with his sister, he’d eventually have to worry about Granny Smith, Applejack, and Babs learning about the affair. Granny would more than likely roll her eyes and try to sweep it under the rug, having dealt with familial canoodling in the past, but AJ and Babs would be wild cards. For all he knew, the mother of his child might abandon him and take their son back to Manehattan with her.

Shaking his head and clearing his thoughts, he dug into his pocket to retrieve his wallet and the tax bill he’d brought with him. Irrespective of how his family reacted, he’d be left twisting in the wind until they got home. The trio, as well as Little Mac, still had just over a week before they returned to the farm, and there was no way in Tartarus he was going to tell them about it remotely, so he’d have to wait until they got back. As he counted out the bits and handed them over to the registrar, he couldn’t help but wonder how his little sister was handling the situation.

Traipsing through and out of town, moving in the opposite direction of the homestead, Bloom pressed into the Everfree forest. Considering everything that had happened with her big brother, there was no way she’d be able to concentrate and sit through classes - as such, she decided that a day of hookie would be prudent. There weren’t many folks in Ponyville she could comfortably talk to about her feelings for Mac, or that she secretly wished to harbor his foal, but there was one mare who might just be able to help her out.

Her excursion through the woodland was short, since she’d made the trek on several occasions before, and it took her roughly half an hour to reach her destination. Walking up to a gnarled, massive tree, the only one of its kind in the forest, she stepped up to the rounded door and issued a resounding knock. If there was one pony who’d be able to help her out, if only with some sage, non-judgemental advice, it would be…

“Zecora!” she bleated, as the door swung open to reveal the tall, mohawked zebra.

“Apple Bloom?” Zecora inquired, cocking her head to the side. “It’s odd of you to skip your studies, particularly without your buddies…”

“Yeah…” Bloom trailed off, hanging her head. “A…Ah wanted to talk to ya about something. May Ah come in?”

Stepping aside and opening the door, the striped mare waved a hand inside. “Come inside and have no fear, I will lend you my thoughts and ear.”

Bloom nodded, saw herself in, and seated herself in the living room. She had to confide her feelings in someone, and the skilled, sympathetic potion-maker was the best option she had - well, for the time being. Sweetie and Scootaloo were both in class, she definitely didn’t want to spill the beans to Mrs. Cheerilee, and both Applejack and Babs were away, leaving her with perilously few options for ponies to talk to. As her host trotted in and sat beside her, bearing a comforting smile, she took a deep breath, steeled herself, and let the cat out of the bag.

She didn’t just talk about the moment of intimacy she’d shared with Mac, but also the feelings she’d harbored for him since being a little filly. While it was a bit odd to profess her somewhat atypical love for her brother, she found herself growing increasingly comfortable as the minutes passed on. For her, the mountainous, tacit stallion that was her eldest sibling was a paragon of masculinity, wonderfully charming, and an all-around perfect pony; it wasn’t her fault that she’d grown increasingly enamored with him over the years, but the impetuous and passionate moment they’d shared had made her realize that she was meant to be with him.

Zecora sat and quietly listened, only interjecting with the occasional question here or there. As Bloom went on, her unease evaporated and she grew more and more comfortable - to the point where she ended up a bit too excited. Grinding her thighs together, with her marehood dampening her panties, she only came to a stop when her host held up a hand.

“I may be able to assist with your large romantic tryst,” the zebra announced, steadily getting to her feet. Crossing the room and to a standing cabinet, she retrieved a small phial of opalescent liquid, returned to her guest, and offered the potion. “With this brew, Mac’s seed will take and show him that your love’s at stake.”

“So,” Bloom began, taking the bottle from the mare’s hand, “this’ll make him love me?”

Shaking her head, Zecora lifted a finger. “It will not make him love you, Dear, but it will make your intention for him quite clear.”

Bloom marveled at the elixir for a moment, digesting the alchemist’s words, before unstopping the phial and downing the contents with two long swigs. If the potion could do anything to help her, regardless of how trivial or inconsequential it was, she’d be more than willing to give it a shot. Turning her head up and shaking the final few drops into her open muzzle, ensuring she got every last bit of the stuff into her mouth, she swallowed and sat the bottle down.

“Alright,” she hummed, quirking her brow, “now wha-”

Her question fell off, feeling a strange warmth grow within her chest. Peering down at herself, wondering what in the world was going on, she felt her shirt shrink - no, it wasn’t her shirt that was shrinking, it was her bust that was growing. Bolting to her feet, alarmed with how quickly the concoction was having an effect, she gnawed her lip and suppressed a rather unbecoming moan.

It wasn’t like she had much experience with potions, never having taken one herself, but she’d seen their effects on others - still, the speed and force with which the elixir struck her left her dumbfounded. Turning in place, trying and failing to watch herself, she marveled as her body steadily transformed. Though she stayed the same height, so far as she could tell, her chest, hips, and backside gradually expanded to several times their normal size.

“I…is this - Oh buck - supposed ta feel this good?” she bleated, clutching her ever-expanding bosoms.

“A bitter drink I would not make,” Zecora snickered, eyeing the girl’s massive mammaries, “for my customers to partake. If your affection, he does return, you may just have a bigger concern…”

Bloom had been about to ask what in the hay that meant, but then she felt a peculiar sensation on the front of her shirt. Pawing at her chest, feeling wet patches of fabric over her teats, she swallowed hard. She’d hoped that her time with Mac would bear fruit, but she would never have guessed that she’d start lactating out of the blue. While she hadn’t felt embarrassed while waxing poetic about her sibling, her sudden metamorphosis made her extremely self conscious.

“Y…ya mind if Ah come back later?” she stammered, keenly aware of her throbbing, winking marehood. “Ah s…should probably get home…”

“By all means, don’t linger here - that being said, please mind your rear,” the zebra smoothly intoned, glancing at the young mare’s enlarged derriere.

Nodding her thanks, feeling herself blushing, Bloom scampered out the door and into the forest. Of all the possible outcomes for her visit to the sage, exotic woman, she had not expected to be leaving in such an unseemly state. Her shirt struggled against her then expansive bust, her shorts had practically been devoured by her rotund rump, and her gate was more than a little awkward, while she weaved her way down the path and back towards town. The good news was that she was no longer worried about potentially courting her brother - the bad news was that she had to get home before anyone noticed how slatternly she looked.

Fortunately for her, since she was very familiar with the area, she was able to skirt Ponyville without incident. She and her friends had spent many a day exploring the area, both in and out of town, so she was acquainted with a number of rarely-used paths and routes to get her back to the farm. While it wasn’t exactly an easy hike, made all the more difficult by adjusting to her newfound proportions, she made it home in less than an hour.

As she awkwardly jogged closer to the homestead, she slowed. She couldn’t say why it hadn’t occurred to her before that moment, but she only then realized that her wardrobe would no longer be adequate for her figure; pilfering a few garments from Applejack’s dresser might do the job, since her sister was considerably larger than herself, but there was an option that would almost definitely work better. Altering her course, she rushed into the barn and up the flight of stairs to Mac’s apartment.

With his errands complete, carrying two bags of provisions over his broad shoulders, Mac crested a hill and spotted his family home. The morning had been a haze, but he’d manage to accomplish his goals without any problems. He guessed it was nearly time for his little sister to return from school, judging by the sun dipping towards the horizon, which both elated and terrified him.

While his jaunt into town had been a small distraction, it had ended all too quickly and left him right back where he’d started. He honestly wasn’t sure what to say or do with Bloom, so he resigned himself to playing his afternoon by ear. If Bloom wanted to talk with him or press the issue of being more than siblings, he’d think of something - if not, despite his barely suppressed desire to give himself to her, he’d let the matter lie.

With a heavy, sullen sigh, he loped into the barn and up the stairs. Before his little sister got home, he’d have to unload the groceries, both for himself and a few supplies for the main house, and start cooking something for them to eat. Bloom’s actions notwithstanding, they’d need some dinner and, if he could dredge up the willpower, maybe a small dessert.

Seeing himself inside, he proceeded through the den and to the kitchen - that was until he realized the door had been unlocked. Someone was in his house, and a nagging feeling in his gut told him exactly who it was. As he sat his purchases down, quietly swearing to himself, he prayed he wasn’t about to get a reenactment of events from yesterday’s afternoon.

He realized Bloom was thirsty as all get-out, but he was not about to make finding her rubbing one out to his dirty laundry a habit. The day before, he’d been caught with his pants down, all but literally, but this was different; this time, he was going to fully prepare himself for the worst. Stomping through the apartment and to his room, forcing himself to don a displeased look in advance, he barged into his room, preemptively lifted his finger, and stopped dead.

His mind reeled, his jaw hit the floor, and every ounce of potential vitriol drained from his spirit, seeing who stood nude by his bed. He recognized Bloom by her face and uniquely styled mane, but her physique left him in a bizarre state of confusion and arousal. Her bust had ballooned to nearly triple its original size, with both her udder-like teats dribbling milk to the floor, but that was only the start of the erotic esotericism.

To put it bluntly, she had somehow become a drop-dead bombshell. Bearing curves that could and in all likelihood would make a whore blush, his once modestly proportioned sister blankly looked back at him. Trying in vain to figure out what in the hell was going on, woefully ignorant to the blood surging to his gradually stiffening stallionhood, it was all he could do to stare in open awe at his sibling.

“Mac?!” Bloom squawked, cursing her unimaginably bad luck.

Wheeling around, she grabbed a clean t-shirt she’d purloined from his dresser, slipped into the nearly fitting garment, and pulled it down to cover her nethers. It wasn’t like she was that bothered with him seeing her naked, especially considering that they’d fucked like rabbits, but she’d only had her enhanced physique for such an insignificant amount of time. Crossing her arms over her chest, covering the whetted cloth over her leaking teats, she knit her brow.

“What are ya doin here?” she asked, doing what she could to seem irate.

Closing his mouth and apparently gathering his thoughts, he pursed his lips and piqued a brow in consternation. To be completely fair, her question had been a bit impertinent, since she was in his room and all, and her indignance faded in an instant. All but wilting under the pressure, feeling bad that she’d been caught fiddling with his clothing a second time, she hung her head.

“Sorry, Ah know Ah shouldn’t be in here,” she murmured, kicking at the carpet. “If’n you’re wondering about - Nnnph - these,” she grunted, hefting one gargantuan breast in each hand, “well, Zecora gave me a potion to help with - uh -”

She cut herself off, unsure of whether or not to divulge the intention of her meeting with the zebra. While she didn’t want to lie to Mac, openly proclaiming her unfettered love for him, as well as her aspirations to have him sire a second foal with her, may not be the best idea. Momentarily stewing on what to say, with her better judgement warring with her desires, she ultimately decided to follow her heart.

“Ah…Ah…” she faltered, clenching and unclenching her fists, “Ah love ya, Mac - not like a brother, but like the perfect stallion that ya are.” Edging closer to him, holding her hands before her heaving chest, she drew a shuddering breath and continued. “Ah don’t want nobody else but you, and if’n that means having a kid with ya to prove it, that’s what Ah’ll do.”

Expressing her feelings for her brother was one of the hardest things she’d ever done, but she wanted - no, needed to hammer the point home. Pressing herself against him, with one hand on his hip and the other on the bulge at his groin, she craned her head up and smiled. Even if he turned her down, she could take some small solace that she’d tried her best.

Gazing down at his dearest sister, watching a tear slip from her glimmering eyes, Mac felt his heart skip a beat. He’d looked after her for her entire life, doing everything he could to protect her and make sure she was happy, and her profound admission rocked him to the very core of his being. There were dozens of things he could have said to comfort her, yet, like so many times in his life, he chose to let his actions speak for himself.

Stooping low and reaching around her legs, he lifted her from the ground, clutched her to his chest, and turned towards the exit. Be darned if he could say how he hadn’t realized how she felt about him, but that wasn’t what occupied his thoughts - no, he was shocked because he only then came to terms with his true feelings for her. If consummating his love for her and having a child was wrong - Celestia help him, he didn’t care.

Marching through his home, down the stairs, and out of the barn, he trotted to the family homestead. They’d have the main house all to themselves, since everyone was away, and he knew exactly what he was going to do with her. Occasionally peeking down at her, seeing her grinning from ear to ear, he fought the temptation to kiss her - not because he didn’t want to, but because he had something special up his sleeve.

As he made his way into her room, breathing in the subtle aroma permeating her chamber, he lifted her head, leaned forward, and locked lips with quite possibly the most special mare he’d ever known. Though he wasn’t fully aware of it, simply thrilled that she wanted him above anyone else, a part of him was elated that he would never lose her to another stallion. Breathing hotly over her face, while he slipped one hand to her delectably cushiony rear, he pressed his tongue into her muzzle and grunted.

Bloom’s hands shot around his thickly muscled neck, as she returned every ounce of his passion. She’d unintentionally teared up minutes before, when she’d confessed to him, yet she found herself weeping tears of joy in his embrace. Never in her life had she been so happy, and she would do everything she could to reciprocate her brother’s love for the rest of her life.

The deep, passionate kiss seemed to last a small eternity, but even then it felt as though it ended too quickly. Feeling herself being lowered, she tried desperately to hold herself to him, to never leave him, yet it was all for naught. He drew his head back, ending the intimate moment, while he stepped forward, bent over, and gently rested her on her bed.

As she lay there upon her sheets, peering up at his towering, beauteous form, her pulse started to race. His adonic good looks and powerful build were only countered by his kind heart and pragmatism, making him attractive in every conceivable way. From the very depths of her soul, she knew they were meant to be together, and she knew just how to give herself to him.

Though it pained her to look away from him, Bloom closed her eyes and pulled the shirt she’d borrowed up and over her head. There was only one thing she could do to mark the occasion, and that was to cement herself as his lover and the mother as his yet to be heir. Flinging the article to the side, then as naked as when she’d been born, she spread and lifted her legs while grinning up at him.

“Ah’m ready, Mac,” she cooed, feeling hot nectar trickle from her aching marehood to the cleft of her ass, “make me a Mama.”

Mac’s heart thundered in his chest, his stallionhood struggled against his pants, and his adoration for her soared to unimaginable heights, as he fiddled with the buttons of his shirt. He could deal with the repercussions of making love to his baby sister later - for the time being, his only concern was claiming her as his own. Growing increasingly frustrated with his garments, he scrunched his nose, grabbed his collar, and tore the flannel garment from his torso.

Ripping his jeans off, heedless of the mess he was making, he undressed himself in spectacular fashion. As he stepped to the very edge of the bed, drinking in her painfully erotic form, he licked his lips. She’d always been an attractive young mare, yet whatever she’d done to herself had dialed up her sensual appeal to an unimaginable level. Ignoring his throbbing cock, bending over to join her on the bed, an idea struck him.

The disparity of their sizes wasn’t a massive hindrance, although there was a position which would be as or possibly even more appropriate for them than simple missionary. Snaking one arm around the small of her back, while her legs closed around his hips, he lifted her from the mattress and straightened to his full height. Their eyes met, the tip of his cock bumped against her entrance, and a spark passed between them, before they kissed a second time.

Being a mere fraction of his size and mass, despite the additional heft she’d gained in curves, he was able to hold her as if she weighed nothing at all. Hearing her effeminately groan into his maw, feeling the warmth of her arousal creeping down his pulsing length, he steadily lowered her and sank into her depths. She was just as wonderfully snug and inviting as he remembered, yet he restrained his bestial urges and allowed them both to savor the moment.

While he did love Babs dearly, Bloom simply held something that their cousin lacked. Unlike the tall, strong, and bull-headed mare from Manehattan, his sister was leagues more genteel, servile, and all-around good natured - sure, he enjoyed his moments of intimacy with the his mate immensely, yet the sweet, tender lovemaking that his sibling offered was something he secretly pined for. Firmly grasping her backside, easing her down his monolithic shaft, he only stopped after he’d hilted the entirety of stallionhood within her.

“It’s so good,” she whimpered, momentarily breaking their kiss and shuddering in his grasp.

While her flattery poured additional fuel on his lustful fire, the sensation of something wet against his torso shook him from his thoughts. Easing her back slightly, yet keeping his shaft firmly entombed within her velvety confines, he gazed down at her mountainous bosoms. Milk streamed from each colossal teat, trailing down her chest and to her stuffed snatch, and the sight was excruciatingly provocative.

“Go ahead,” Bloom purred, lifting one enormous breast towards his face, “Ah’m sure our foal could use a little help draining these puppies.”

Flashing her a grin, he shot forward, wrapped his lips around her nipple, and vehemently suckled upon the sensitive bud of flesh. She gasped, beset by the wondrous feeling of being nursed on, and reflexively clenched her depths around his length. Having him suckle her milk felt astounding, far and away more pleasurable than simply having her tits played with, and she could quickly see herself getting addicted to it.

“M…Mac,” she whined, running her fingers through his mane, “Ah need ya…”

Grunting around her teat, he simultaneously rolled his hips back and lifted her slightly, freeing a portion of his shaft from her taut marehood, before he began fucking her in earnest. Her toes curled, she could feel her entrance being drawn out and crammed in with every thrust, and she was unable to stop the whimpers of delight from escaping past her lips. Though they’d only just started, she could already tell that she wasn’t going to be able to last long.

The physical sensations of him sucking her breast and pounding her cunt were amazing, there was no denying that, but the fact that she knew he was taking it easy on her was what really got her excited. He wasn’t fucking her like some unknown harlot in a back alley, simply an outlet for his sexual desires - he was making love to her, relshing her, and it was easily the most pleasurable experience of her relatively short life.

Her fingers sank into his back, she rhythmically constricted and relaxed around his pistoning stallionhood, and her eyelids fluttered, as a sensation of warmth grew into an inferno within her abdomen. She’d had more climaxes than she cared to admit, both with herself and her prior flings, but this felt different; not only was the sensation welling up within her vastly more powerful than anything she’d felt before, but it seemed focused in an area just below her navel.

While she rode her stud, doing what she could to pleasure him, a miraculous thing happened inside of her, yet she had no way of knowing it at the time. Zecora’s potion was the ultimate tool of those wishing for maternity, priming her reproductive organs and sending them into a frenzy. Growing ever closer to release, she was woefully ignorant to the two eggs which lazily drifted from her ovaries and into her womb.

Huffing around her nipple, swallowing down mouthful after mouthful of her milk, Mac subconsciously increased his pace. In his time with Babs, both before and after she’d given birth to Little Mac, he’d developed an unbridled fetish for lactation. Heck if he could explain why he was so turned by a big, soft pair of milkers, but he viewed them as a mark of fertility and they really, really got his motor running.

Crushing her womb with every herculean thrust of his hips, working up a sweat in the process, he shifted his head and suckled from her undrained tit. She felt fantastic, far more snug than Babs while being just as durable, and he railed against his domineering urges to go fuck her brains out. As he fought to reel in his inclination to subjugate her, her orgasmic wail and gushing snatch sundered his higher functions.

To think that he’d made her cum with so little effort was as rewarding as it was arousing, and he lost himself because of it. Stepping forward and pressing her to the wall, he plowed her with all the inexorable force of a freight train. If - no, when he knocked her up, she’d never leave the farm or his side ever again. Detaching from her breast, with milk dripping from his chin, he lifted his head and drove his tongue into her howling maw.

Lifting her arms and locking her hands around the back of his head, returning every ounce of his passion, Bloom weathered the calamitous storm that was her climax. She could feel his desire to breed her, to claim her, and the thought of devoting herself to him drove her wild. Flexing her legs and bucking herself against him, she returned his vehement lust with lasciviousness of her own.

On and on they went, rutting like a pair of crazed animals, yet they didn’t stay exclusively in one spot. They screwed on the bed, the floor, over the dresser, and anywhere in the room which they thought was capable of enduring their combined weight - unfortunately for the two of them, neither of the siblings were doing much thinking. The path of destruction carved by their wanton screwing was marked by shattered furniture, crumbling drywall, and ruination like the homestead hadn’t seen since Pear and Bright had first done the deed.

In spite of having climaxed no fewer than a dozen times, leaving her mind in a haze, the sensation of his stallionhood flaring within her, while his length pulsed in tune with his heart, ripped her from her blissful stupor. Laying atop what remained of the bed, with the frame having collapsed beneath them at some point, she locked her legs around him and buried her face in his shoulder. At long last, she was finally going to get what she so desperately wished for.

“Breed me!” she brayed, grinding against him. “Give me your - Aaaaaaaahnn!!!”

Her plea became a rapturous shriek, as he plunged into her womb and erupted like a geyser. The ecstasy of being impregnated was unlike anything she’d ever experienced and she could tell it was an apocryphal moment for herself. In that moment, she became his mare for the rest of her life.

Billions of sperm rushed into her fertile depths, each seeing out a target, while Mac fitfully humped into her and ground to a halt. He’d railed his baby sister a second time, and something told him it was going to be far from the last. Draping himself atop her, heaving air into his lungs, he sluggishly looked around.

The room was an absolute mess, the floor and some areas of the walls were speared with Bloom’s climactic juices, and he’d more than likely have to repair or outright replace all the furniture, yet he had no regrets. As far as he was concerned, the devastation was a small price to pay for what he’d gained. Rolling to the side, taking care to carry her along with himself, he lovingly held her to his bosom and savored the warm afterglow of their heated afternoon.

Pressed against her, he was unable to see the full extent of what his infatuation had wrought. A small, apple shaped sigil, being almost a mirrored image of his cutie mark, appeared on her cum-swollen belly. Being unaware of the seal’s emergence, the pair simply enjoyed the afterglow amidst the destruction.

“Mac,” Bloom whispered, shifting slightly to peek up at him, “do ya really love me?”

Mac smiled and affectionately stroked her back, as he rested his head over her shoulder. “Eeeeyup…”

“Ah ment it too,” she giggled, pecking her nose and rolling atop him.

Pushing herself up, if only to fully appreciate the sheer volume of Mac’s jizz in her belly, she leaned forward, gazed down at her stomach, and went rigid. It was only at that moment that she spied the mark on her abdomen. Cocking her head to the side, she slowly looked up at her brother’s face.

“Mac, does that mean what Ah think it means?” she quietly asked, with her excitement steadily growing.

While he wasn’t entirely sure what the sigil meant, he leaned heavily on his instincts, beamed up at her, and snatched her into another hug. “Eeeeyup!”

The mess they’d made was catastrophic, they were both slathered in sweat, and a dull ache crept into their frames, yet it had all been worth it. Their bond had grown to something unbelievable, strengthening and transforming from mere brother and sister to paramours, and their lives were made all the more whole because of it. Locked in an intimate embrace, basking in the comfort they afforded one another, they put aside their fears and doubts while sharing each other’s warmth, comfort, and security…