The Return of The Growth Word

by The Irish Brony

Rating: mature
Tags: Sex, Profanity, My Little Pony: Friendship is Magic, Alternate Universe, Human, Romance, Porn, Fetish, Rainbow Dash
Length: 3049

Rainbow Dash has come back home to her human friend Joe from an emergency meeting with Celestia. She has brought back a little toy that can bring back the rush Dash use to feel foe sex.

Rainbow Dash has come back from a week-long journey to Canterlot for an emergency meeting with Celestia and she is horny for her human friend Joe. But this time it's going to be different. It's been a year since Dashie lost the ability to grow bigger. Good thing she knows a good scientist that can help her make a collar for that exact reason.

Sex:Growth, mare on human, human on mare, light face sitting

Published 2023-08-04 22:40:01 UTC
Last updated 2023-08-04 22:40:01 UTC

The Return of The Growth Word

Joe hums to himself as he stirs the pot full of soup with a smile on his face. Rainbow Dash and her friends had gone off to Canterlot for some emergency meeting with Princess Celestia, which left the tall, dark-skinned human to his own devices for a week. He didn't mind much. It allowed him to do things that Rainbow Dash wouldn't have found fun, like sitting by the fire and reading an entire book in one sitting. Well ok, Dash would have done it with Darring Do or Space Team, but not with other books. Today was the day they were coming back meaning Dash would probably be hungry from the long train ride to get to and from Canterlot. And as if on cue, the pot boils the moment the door opens up to the house.

"Joe! I'm home!" Dash yells, flying into the house before hovering a few feet off the ground. Strapped to her back is her light blue saddle bag with the latch as her cutie mark. Joe smiles before turning the burner on low and walking out of the kitchen. "How's my favorite human doing?" Dash asks, closing the door before turning to face him as he walks out of the kitchen and into the living room.

"Only human," Joe responds with a smile. "And better now your back,"

"You missed me that much?" Dash asks, hoovering a bit closer in his direction. Her eyebrow raises in genuine curiosity.

"It was fun not having you around telling me that the stuff I do is boring," Joe says, crossing her arms over his chest before sighing. "But I did miss your undying charisma and beauty,"

"You missed my rump," Dash bluntly responds with a cocky smile.

"That too," Joe admits. "No mare has the toned butt like yours,"

"You bet," Dash responds, placing a hoove on her chest with a confident smile spreads across her face. "Now how pent up are you?" Dash asks, leaning down and pushing her rump into the air.

"Very," Joe responds, already feeling his boner pushing against his pants. "But not horny enough to just fuck right now, there's dinner to be eaten,"

"Oh please tell me you made the soup?" Dash asks, correcting her poster and clapping her hooves together like a little filly as her mouth waters in excitement.

"Oyster soup without the oyster," Joe responds with a smile.

"You're the best," Dash says, quickly flying over and hugging Joe. Before Joe could hug her back, her face lit up in realization. "Oh!" Dash pulls away before digging through her saddle bag. "That reminds me. I've got something extra special for tonight's bedtime fun,"

"What is it?" Joes asks, trying to see into the bag.

"I might have gotten my hoofs on something ponies have been dying to get," Dash says, pulling out a silver collar big enough to fit around her neck. Sitting in the center of the collar is a blue gem with a dial next to it.

"No," Joe looks at the collar in her hoof in disbelief. "How did you get your hands on the growth collar?" Joe asks, gently taking the collar from her hoof.

"I may or may not be friends with the scientist behind the invention," Dash says, pushing invisible dirt off her shoulder with a big smirk on her face.

"You're friends with Dr. Flask?" Joe asks, looking up at her.

"Not friends, more like..." She waves her hoove in a little circle like a human hand would do as she tries to find the right word. "Companion," Dash says, just causing more confusion on Joe's face. "I was in flight school with his brother so now I know him too,"

"Oh," Joe says, finally understanding it before handing the collar back. "Makes a bit more sense,"

"Food first, then we can have some fun," Dash says, taking the collar from his hand before wrapping her hoofs around his neck and pulling him into a kiss. Joe smiles before wrapping his arms around her neck and kissing back. His hands gliding through her messy rainbow hair as his lips glid across her soft lips.

Joe pulls way before saying, "Sounds good,"

"Now it's time for some fun," Dash says, putting the collar on as the two walk into their bedroom. "You ready big guy?" Dash asks, flying up and closing the door behind them and locking it before turning back towards him.

"I'm guessing you're not going to tell me the growth word are you?" Joe asks. Dash eyes up his body with a small smile before flying up to him. She pushes her chest against his while wrapping her arms around the back of his head.

"What fun would there be in that?" Dash asks before kissing Joe passionately on the lips. Joe sighs before closing his eyes and wrapping his arms around her neck and kissing back. His hands gently rested against the back of her head as he pulls her closer to him. The blue gem on her collar starts to glow, causing the area around her neck to glow. The light blue glow slowly creeps across her body before engulfing her entire body. That's when the magic kicks in, causing her body to start slowly growing in Joe's arms.

Dash's body shivers as she lets out a happy moan into Joe's mouth. Her body quivering in both anticipation and pleasure as it grows. The magic stops, capping her growth at just two more inches than her normal height. Dash pulls away from the kiss with a blush already on her face with a big smile to go with it.

"And let the game begin," Dash whispers seductively. She gently swings her hips a bit, causing her nethers to drip out a bit of her cum down her leg. She then tackles him to the bed, wrapping her arms around his back as the two fall down onto the soft bed. The two laugh as the bed bounces them back up a bit before settling down.

"Here we go again," Joe says, wrapping his arms around her body. "Should I just start listing off words?"

"That sounds like a bad idea," Dash says, the gem already glowing again. "Just sit back and relax," Dash leans up and kisses him on the lips. Joe kisses back, wrapping his arms around her neck before sliding them down her body toward the base of her twitching wings. His fingers gently place themself around the base of her wings before gently massaging the muscles around the wing. Dash's entire body seizes up as her wings go flying out to both sides. She lets out a moan of delight as the magic starts to take hold again.

Dash grinds her hip against his as her body starts to grow bigger. Her body shivers as the pleasure is fuelled by Joe's hands and the growth magic. Her butt starts to slowly grow more round and plump than it was before. Her wings become that much more majestic with each inch added to her size. The magic stops, placing her at about four more inches added to her body.

"Aahhh, fuck I've missed this," Dash moans, pulling away as her eyes threaten to roll up into her skull. "It feels like no heat I've ever had,"

"I think I've kinda missed this side of you too," Joe says, sliding his hands down to her butt before gently squeezing her round rump. Dash nuzzles into his chest as she lets out a moan of pleasure. She smiles up at him with a devious smile.

"I think you should take off that shirt and those pants so we can start having some real fun," Dash says, sitting up. She looks down at him with a big smile. With her wings spread out, she almost looked like an angel from Joe's angle. Before Joe can respond, Dash lets out a happy moan as she closes her eyes. The light blue magic washes over her body like water before it causes her to grow. Her body was now growing fast enough to be seen by Joe. She instinctually humps Joe's hips as her own hips start to grow a bit faster than her body.

"Someone like's what they see," Dash says as the magic stops. She looks down at him as she feels his boner brush against her hips.

"Hard not to like a growing mare," Joe says, gently squeezing her slightly bigger thighs. Dash smiles as his fingers slightly sink into her thighs.

"Now what did I tell you about those clothes?" Dash asks, looking down at him in mocking disappointment.

"Just get off of me then," Joe responds before pulling his shirt off. Dash rolls her eyes and get's off of him and sits down next to him on the bed. He sits up and slides off his shorts and underwear before pushing them away onto the ground with his feet. "Better?" Joe asks, turning to Dash.

Dash jumps up and pushes him to the bed. His head hitting the pillow with her looming over his body with a big smile. "Much," Dash says, licking her lips. "Now that's what I was looking for," Dash says, sitting down between his legs and right in front of his throbbing dick. She licks her lips before swallowing his dick in one go.

Joe's hips thrust up into her mouth as he lets out a surprised gasp. Her warm mouth wrapped around his dick with her tongue licking the underside causing surges of pleasure to run up his back. Dash smiles to herself before bobbing up and down on his throbbing cock.

"Now that I really missed," Joe moans as he times his hips with her head bobbing down. Dash chuckles as the blue crystal on the collar lights up again. The magic runs up to her head and down her back all the way to her butt. She lets out a moan as the growth starts up again like an engine. Her body slowly grows bigger and bigger as she continues to bob on his dick. Her wings quiver a bit as they get a bit of the growth magic. She shifts a bit and raises her rump up in the air to show off her growing buns to Joe. Her butt was now the size of a normal beach ball and still getting bigger. Dash pulls off his dick as the magic stops. She is now twice her normal height and smiling down at Joe between her hooves.

"Now it's time for some warm-up exercises," Dash says with a smile before turning around and sitting her massive rump against his chest and right in front of his face. Her dripping slit covers his chest in her pre cum. Joe smiles before grabbing her butt and pulling her closer to his face. She grunts in pleasure before letting out a loud moan as his tongue slithers into her body through her cunt. He gently squeezes her very blush rump while licking the entrance to her slit. "Now that hit's the spot," She moan as he squeezes her rump again.

She lets out another moan as her heart beats faster. The magic starts up again, this time almost stronger. Her face turns bright red as her wings spring out. She thrusts her butt harder into his face, causing her to moan as his face pushes against her soft and growing rump. Her body quivers in pleasure, for what took four growth sports now does it in one. Her body grows double its previous size as her rump starts to engulf his face, growing to the size of a yoga ball.

Dash bites her lower lip as the growth slows down. She tries to hold back her urges, but losses as Joe's hands explore her bigger body. He reaches around to her hips and finds the muscles right by the joints before squeezing hard. Dash's body sizes up as she lets out a moan in surprise and delight. She bucks her hips deeper into his face, causing his tongue to slide deeper into her and slide her over the edge.

"AAHHH!" Dash shuts her eyes and grits her teeth as she humps his face. Releasing all of her cum right onto his face. She slows down before relaxing entirely. She stands up on her shaky legs before laying down next to Joe. He attempts to wipe away the cum, but just makes a bigger mess on his face.

"Wow, your huge," Joe says, looking over at Dash's new size. She now lays the same length as he does. Her butt was absolutely massive and juts out on either side of her body. Her wings, matching her new size, were now like angel wings.

"And it feels amazing," Dash says, scootching a bit closer to him before nuzzling her head into his neck. "But it would feel better if you would fuck me," Dash says, looking into his eyes with as much pleading as she could muster.

"I guess that would only be far," Joe says with a big smile.

"You figured it out," Dash says as the collar starts to glow.

"The word is that?"

"I asked for a word that would be easier to say during sex than everyone," Dash says as Joe gets up onto his knees. Dash stays laying down as the magic slowly creeps across her body. Her wings twitch as her face turns a bit red. Her body starts to grow bigger, much bigger and much faster. The magic had been amplified by the two times the word was used, causing her to grow much faster and bigger. Her rump doubles in size almost instantly as her body starts to creep off the bed. Joe slides off the bed as Dash's legs slowly grow and dangle off the bed. Her hooves touch the ground and her head almost hits the backboard.

"Wow," Joe says with a blush on his face as the magic stops. Her body had just doubled again in size. She was now slightly longer than the bed and almost wider than it. Her butt was now so big she probably wouldn't be able to fit through the door. Joe's dick throbs in anticipation as his eyes lock onto his target, her big plush rump. He moves behind her hips that come almost up to his chest and splay out about half his arm span. Her cyan-blue fur and giant cutie marks are just urging to be squeezed, so Joe does as her butt wants.

"UUhh!" Dash grunts as a moan follows quickly after as Joe squeezes her butt together. His hands sinking into her massive rump, almost disappearing into her cutie mark. Her wings shake as Joe gently massages her rump with his nimble fingers. "Don't stop that," Dash moans as her heart rate skyrockets. The collar lights up as her body is flooded again with its magic. Dash's wings struggle to stay closed as her mind is flooded with pleasure. Joe's hands sink deeper into her plot as her body starts growing again. Her wings stiffen out and hit the ceiling as the bed creaks and groans from the pressure applied over its surface.

Joe bits his lower lip as his face goes flush red while he watches her hips slowly grow and start pushing up against his throbbing cock. The growth stops, placing her just bigger than the bed and quite thicker. Her butt was now almost out of his reach. He decides to slide his hands to her hips before gently sliding his cock into her surprisingly still-tight pussy. Joe and Dash share a mutual moan together as he slides himself hip-deep into her before situating himself for maximum thrusting.

"You ready Dashie?" Joe asks, gently pushing his hip into her butt while pulling on her hip.

"Ahh... Yes, please rut me as hard as you can," Dash says, her cunt dripping out cum in anticipation.

"As you say so Dashie," Joe says before pulling out and thrusting hard into her. He starts out with a slow but hard rhythm before slowly speeding up. Her butt conforming to his hip thrusts and pushing her into the bed's backboard. Dash's body shakes as her eyes roll up into her head. She braces herself against the backboard with her hooves as the entire bed shakes from Joe's powerful thrusts into her massive and chubby rump. Cum slowly drips down her leg as he quickly slides in and out of her vice-like pussy. Her massive butt acting like giant airbags for his hard thrusts. He gently squeezes her hips, causing her to shiver as his climax starts to peak.

"I'm close Dash!" He grunts as weeks worth of pent-up cum threatens to bust right in her at just the mere feeling of her massively soft rump.

"C.. cum in m.. me and show me w.. who's boss," Dash says, her entire body shaking in anticipation as her own pent-up cum starts to peak again. "I want all of you buried deep into me,"

"As you wish," Joe grunts out before pushing himself deep into her butt. He pushes her up onto the bed with his last powerful thrust. His dick releasing his cum deep inside of her. Dash lets out a moan as the warm liquid fills her up. Her leg's shaking as she lets her cum flow and mix with his. Joe relaxes as he takes deep breaths, his heart beating a million times a second. He fully pulls out of her before climbing on top of her and laying his head onto her massive and squishy plot.

"Who needs a bed when ya got a mare butt," Joe jokes, looking over at Dash. She was also recovering as she looks back at him with a smile.

"You comfortable on my massive butt?"

"Probably more comfortable than the bed," He responds.

"Pegasus butts are supposed to be as soft as clouds,"

"That's why I like your butt so much," Joe responds, causing Dash to laugh as the two slowly start to fall asleep. "I missed ya, you big girl,"

"I missed ya too," Dash says as the two drift off to sleep.