As if a weight had been lifted from his shoulders, Shining let it all flow out, like a collapsing dam. “Gods, I know it’s so wrong, Twily. I’m so sorry. But I want to bend you over that coffee table and buck you silly - I’ve always wanted to do that, ever since we were foals. But I’ve never wanted it more than now. I want to take you, Twily. I want to make you mine.”

Twilight blushed, feeling tears forming in her eyes. “I-I… I want you to rut me too… Shining. I want you to do it.” She felt her ears flatten back, and she shrank into her shoulders, almost dizzy with the rush of what she’d just said.

“R-really!?” Shining gasped, breathlessly.

Twilight nodded. “I… I don’t know what to do… but… I want you. I want to do it… with you.”

Shining scooted up, quickly jumping to his hooves, taking his little sister’s chin in his hoof, and moaning “Twilight…”

Then he kissed her.

Deep and passionately. Not like a brother. His powerful tongue thrust into her tired mouth, overwhelming her, dominating her inexperience, leaving her completely at its whim as it traced along her teeth and gums. Then, just as she was settling in to the fiery heat of his kiss, he pulled back, breaking their connection. Twilight almost fell forward into him. Her heart was pounding so hard, she felt so dizzy… was this really going to happen?

“Sorry Twily… but… I can’t… I can’t wait anymore.” Shining groaned, twisting his little sister by her shoulders, so that she was facing the coffee table.

Twilight felt her brother’s powerful hoof push her forward, making her front legs step up onto the small wooden table. She wasn’t resisting, but there was something so… feral… so masculine about how her brother was moving her around. Is this how mares feel, when they’re with their lover? Or is this just because of Shining? She looked back over her shoulder with a bit of fear… she saw with some embarrassment that her plot had stuck itself proudly up in the air, instinct and biology completely taking over as her tail flagged up high, giving her brother and the two spectators on the couch a full view of her nethers. She didn’t care.

Shining nickered, stamping one of his hooves as he caught another whiff of Twilight’s rear. He looked down at her delicious plot and took a deep snuffling snort of his sister's fragrance.

Twilight felt a shudder wrack her as she realised what was about to happen. Her brother was drinking her essence in, preparing to rut her… to fuck her like their ancestors, wild stallions on the grassy plains of Equestria, would have millions of years earlier. She felt her pussy quiver and clench, twice, thrice. Fat winks of her clitoris as it shot in and out right in front of her brother’s nose, splattering a messy splotch of marejuice to their parent’s hardwood floor.

Shining dipped his head, pressing his nose and tongue against her cunt, snuffling and lapping, the thick muscle of his tongue winding its way between her tight, grasping folds. Twilight threw her head back, letting out a plaintive little wail as she writhed on her big brother, spreading her hind legs wider as she did.

“Shiiiinnnniinngg….”

“Buck me, you’re ready… Twily.”

Twilight dizzily opened her eyes as she heard the heavy clattering hoofsteps of the former captain of the royal guard step over her, mounting her. She felt a rough hoof on the back of her mane twist her despondent head around so that it was facing forward, looking down at her own hooves. She could see the big white, unshorn fetlocks of her brother as he placed his heavy forehooves on the outside of her own. She felt the heat and size of his barrel as it slipped over top of her, felt the huge and heavy hot breaths of his powerful lungfuls of air wash over the back of her neck.

Big. He’s so big. He’s always been bigger than me… but he’s just… enveloping me… encompassing me… overwhelming me… Gods… I belong to him now. Twilight groaned as her mind raced. Then she felt it, laying on her back.

Huge. Hot. Wet. Heavy… so heavy…

The damn thing reached up to the middle of her spine!

Shining stamped his left hoof, letting out a little whinny, before picking up his right hoof, trying to position his huge cock, as he shifted his weight backward to give himself more room to align himself with her winking pussy.

“Sh-shining…” Twilight groaned, thrusting back obliviously… not sure what she was doing, but hoping to grind herself against something… anything to relieve the need she felt.

“Buck!” Shining grunted, putting a hoof between his little sister’s shoulder blades and shoving her roughly forward and down, pinning her chest against the coffee table and making her stick her ass even more up into the air, as he pressed her cheek into the unforgiving wood.

Twilight suddenly felt it. The thick bulge against her pink, twisting opening. It felt so good, the perfect object for her to grind against, for her to find the relief she wanted. It felt so right. She moaned and pressed back, only to feel her brother’s cock slip from her furrow, sliding up her asscheeks and bouncing off her tight ponut and slapping off Shining’s chest.

“Hey!” Shining put his hoof back on her shoulder-blades and pressed again, adding the weight of his body to her back, pinning her in place. “Relax! Relax!”

She nickered involuntarily. She’d never nickered before. Her stud was telling her what to do, to control herself so he could rut her, she thrashed slightly under his weight then held still, feeling him make another approach.

This time… if connected.

“B-buck… l-like fucking a foal.” She heard Shining groan as he started to pierce her.

His massive girth was straining her, stretching her. None of her toys came close to this. Her breath kept catching in her lungs, the ache of her walls parting so wide it sent a pang of fear through her. He’s going to split me in half! He’s going to break me! she writhed but found no purchase against the steady grasp and slow, insistent thrust of her brother. Deeper and deeper he went, plumbing far past anywhere Twilight had ever dared in even her most frantic explorations…. And for every inch deeper he drove, fucking into her velvet depths, her aching pussy was strained wider and wider by the increasing girth of his fat stallionhood.

“Shinnninng…. It’s…. Too big!” She felt the words fall from her mouth, just like her tongue. But it was a lie. He was perfect. The strain was already turning into something entirely different, a feeling she had always read in those harlequin novels but never understood: she was being filled. Not just her marehood… but her need… her desire… her spirit.

She loved it.

Shining paid no attention to the writhing, groaning little alicorn mare under him, slowly scooching forward with his hind legs, step by step, as he pressed more and more of his huge, long, fat stallionhood into his beloved little sister.

She was stuffed. Her pussy ached with pleasure as her brother’s medial ring roiled against her opening, pushing the tight, gripping pink lips inward as they tried and failed to permit the sudden expansion in his thickness… straining, resisting… then finally giving in and letting him sink a sudden 3 inches into her.

“Ahhhh!” Twilight’s wings shot out to either side. She felt her cunt quiver and clench, spasming in shocks that drove her wind from her lungs. A sparkle of magic built up in her horn, unbidden, spilling out in little involuntary sparkling fireworks that rained down to the coffee table with a gunpowder smell. The magic sparked through all her nerves, racing out from her clenching pussy through her stomach, all along her spine, out to her very feather tips… then exploding in her brain, flooding her with pleasure.

She was cumming. On her brother’s dick.

“Fuuuck!” Shining exhorted, as little Twily’s cunt milked his stallionhood for all it was worth. The alicorn’s swollen clitoris, mashed against the wall of her lips by his tremendous girth, shot in and out with abandon, schlicking marecum all over the remainder of his shaft and his massive black balls. He was pressing up against her cervix now, the head of his cock pushing the soft interior of her womb. And he still had 4 inches in the cold, black skin uncovered either by condom or sister-pussy, frighteningly thick… he had to bury himself in her… to take her completely. Only Cadance had ever been able, not even the more experienced guard-pony ‘comfort mares’ could take him. But he needed to take her completely. There was no stopping this ride.

Shining grit his teeth and slammed forward with his hips, rocking his alicorn sister forward with a violent thrust that made her squeak through her orgasm. The leverage he’d gained with his hoof on her shoulder blades was perfect, letting himself slam roughly into her, using the force of his powerful legs to drive more cockflesh into her virginal cunt.

“Sh-shining…” Cadance began to warn.

“Buck off…” Shining grunted through his nostrils, as he roughly fucked his little sister. He was all the way gone, a stud breeding his mare, a being of pure lust. He wasn’t going to be stopped. Not by anypony.

Twilight moaned out as she felt something inside her slip, felt the huge head of her brother’s cock slip into her womb, plunging into what felt like her very heart and soul, something so deep and secret… had been invaded by her stud… and she loved it.

“Y-yyesss!” Twilight moaned out, as her brother slid even deeper into her, his huge girth impossibly fitting into Twilight’s marehood.

She felt a sharp pain in her neck, then the pulling of her mane. He nipped me. He’s pulling my hair. He’s taking me. Yes. Yes! Twilight groaned out, feeling Shining with a mouthful of her mane, as he jackhammered into her from behind. Harder and harder, faster and faster, until she felt it… his cock slip even deeper, pummeling the far side of her womb, as he hilted his huge studhood in her body. The obscene bulge reached all the way up to her breastbone.

Twilight quivered again, like a bolt of lightning had just torn through her. The orgasm that had never ended flared up into a raging intensity once again, her squeaks coming out in incoherent fits, rising to a scream as her brother stopped penetrating her… and began to fuck her.

The heavy slaps of his balls as they slammed against her pussy and teats, swinging back and forth with each piston, came with showers of juices being flung back and forth, a result of her abused, aching marehood gushing in desperation as she lubricated her brother’s shaft.

SLAP SLAP SLAP

The heavy sound of flesh impacting flesh filled the living room.

CREAK CREAK CREAK

The grinding sounds of the coffee table sliding against the hardwood floor under the assault of Shining’s powerful, impactful thrusts.

“Ahhnnn ahhhnnn ahhhhnnn! Yes… yes! YES!” Twilight’s squeaks became screams, as she lost herself to the pleasure.

“Tw… Twi! TWI! TWILY!” Shining grunted out from behind the mouthful of his little sister’s purple hair, his stamina running out as the milking, clenching, grasp of his little-sister’s slick vagina brought him closer and closer to the edge.

“YES YES YES! F-FUCK… FUCK ME!” Twilight screamed, pushing back with all her might. Her hips colliding with the jackhammering piston of Shining’s potent final strokes.

“Fuuuuuuuuckkkkk!!!!” Shining groaned out with a death-knell of a scream, before locking his legs forward, jamming himself as deep into little Twily’s body as he could and holding himself there, his balls clenching and jumping up to his shaft, little quivers wracking his body as he emptied himself in her.

The bulge in Twilight’s womb expanded outward, pressing under her belly button as her big brother’s flare grew three sizes inside of her, torqueing and twisting with the heavy rush of blood that made the whole cockhead expand terrifically in mere moments. Then Twilight felt her womb flood with heat. A spilling fullness that grew and grew, with spurt after spurt as her brother grunted out in her left ear, over and over, jerking and thrusting into her.

She felt the splattering spurts as they grew the bubble inside her, felt her belly pooch out and expand as her poor little body was stuffed with virile, thick, potent cum. The rush of endorphins, the sensation, the exertion… it was all too much, and she felt her rear legs cramp, and give out.

Not that it mattered… Shining’s potent, jerking, ejaculating cock supported her rear, holding her up in the air as it fired rope after rope into her, the biggest load of the entire night, absolutely stuffing her cervix. Twilight groaned out, the feeling of satisfaction totally beyond anything that she ever thought that she’d be able to experience on Equus… a feeling of total contentment. Not just because she’d been completely satisfied, as only a mare could ever hope to be.

But because it had been her brother who’d done it.

She let her head fall onto the coffee table, her eyes rolling happily as her panting tongue flopped again from her mouth.

On the other end, Shining finally drew a deep breath, his last spurts emptying out of him. He released his little sister’s tail, finally finished, finally satisfied. The beast within him sated. He couldn’t believe what he’d just done… but he didn’t regret a moment of it. It was the fuck of his life.

With a dopey grin, he basked in the feel of his little sister’s pussy around his softening cock. His head lolled over to the side and he twisted to look with a half-drunken grin at his beloved wife who’d helped him to this moment.

But she only had a look of complete shock and surprise on her face.

Through the foggy haze of post-orgasmic bliss, Shining wondered just what was bothering her so much. Was it that he had snapped at her? No, she’d understand something like that. And Cadance loved when their bedroom play got a little rough. So why…

Then Shining felt it. The dripping splotches falling from Twilight’s quivering marehood as he shrank and withdrew from her. It wasn’t the steady drip of sticky marecum… it was the inconsistent plops of thick, stallion-spooge.

He looked down, his gut already stewing with concern, but he had to confirm…

There, like an obscene fountain coming out of his little sister’s plot, stuck high up in the air for everypony to see, was a waterfall of his thick, very potent, very active, very impregnation-causable cum spilling from her clenching marehood… as his penis slipped from her form, revealing the snapped condom that had not survived the frenzied buck.

“Oh… oh BUCK.”

Cadance groaned. “Well… we did say that Flurry could use a sibling.”

Shining moaned out again. “Oh BUCK.”

Starlight chuckled. “Guess that Twilight’s going to have to try to collect AGAIN after all.”

Shining moaned out again. “Oh BUCK.”

The lights snapped on in the living room, and Twilight Velvet and Night Light’s voices called out as they rounded the corner. “Hey, just what’s all this racket down here…?”

Twilight Velvet piped up as her eyes adjusted to the light. “Your Dad and I could barely concentrate on… oh my.”

Shining groaned out again. “Oh BUCK.”

Celestia appeared in a flash of light in the middle of the room. “Twilight! It turns out that I accidentally replaced your birth control potion with my hyper-fertility medication, I came as soon as I found out in case there was any possible accident!”

Shining groaned out. “Oh BUCK.”

Luna appeared a moment afterwards. “Sister! Halt! I told you that I’m live-dreaming your actions to all citizens of Equestria, they can currently see and hear everything that you can, you must return to the palace at once!”

Shining groaned out again. “Oh BUUUUUUUUUUUUUUUUUUUUUUUCK.”

The wall of the house suddenly exploded inwards, a large pony-shaped pitcher of Kool-Aid standing there, with the mail mare from Ponyville bathing inside the red-liquid sloshing interior.

“OH YEAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!”

The End.

Author's Note

I am so sorry for the ending.

Well... not if you're xRei or Shake, this ending was deliberately to try to get an eye-roll out of you, if I did I'm happy.

Don't even ask how Derpy got in there, nopony knows how she does it.