Ivan walks up to Derpy's small cottage holding a box of specially baked muffins from Suger Cube Corner. Ivan pulls down his red and blue scarf before knocking on the door. He shivers as the cold winter wind hits his face. The door opens, and he is met with a big smile from a smaller than average gray mare with derpy eyes.
"Hello Iven," Derpy says, looking up at him happily. Ivan chuckles at her missaying his name. "Come in, it must be cold without fur,"
"Thanks?" Ivan says questioningly as he steps into the warm cottage. Even though she was his mare friend, it didn't mean he stopped questioning her choice of words. Ivan places the box on the little table at the entrance and starts taking off his winter coat and scarf. He puts them near the entrance as Derpy looks at the box.
She sniffs the box before exclaiming happily. "Chocolate Muffins!"
"Specially baked by Pinkie Pie herself," Ivan says, patting her on the head while grabbing the box. The two make their way to the fireplace which has a decent fire going. They sit down, placing the box in between the two of them as Derpy lays a wing around Ivan and pulls herself closer to him. He wraps his arm around her back before opening the box. The smell of cooked muffins spread into the room, causing their mouths to water. The two grab a muffin and take a bite.
"Mmm, it's good," Derpy says, before taking another big bite. Ivan takes more modest bits of his muffin. He looks down to realize the box was still full even though they had taken two out. Ivan moves uncountably as a warm tingling sensation forms around his crotch. He thinks little of it as he takes more bits. Derpy had eaten the first and now was going for a second. Ivan fells her rump press against his hip. He looks down to see her plot seemed to be bigger than her normal bubbly butt.
"Derpy, you might want to slow down, or else you might end up with a bigger butt," Ivan says jokingly. He finishes his muffin and grabs another. Derpy scarves down her second muffin.
"God she's beautiful," Ivan thinks as he mindlessly takes a bit of his muffin. Lustful thoughts about fucking Derpy senseis fluid his mind, causing his dick to get hard. He shakes his head as Derpy starts on a third muffin. Ivan then realizes Derpy was taller than normal. He looks down to see her butt was firmly squashed against his hips.
"Derpy," Ivan says, stopping Derpy mid-bite.
"Ya?"
"I think a certain Pink pony got help from a Purple Unicorn to spike our muffin with a spell," Ivan says, staring into Derp's one good but very beautiful golden eye. She looks down and scoots away from Ivan while retracting her wing. Her plot was definitely a few inches bigger than normal.
"Wow, that explains the lustful thoughts I just had," Derpy says nonchalantly before looking up at Ivan with a smile.
"I know that smile," Ivan says, placing down his muffin.
"Can we?" Derpy asks, tilting her head to the side cutely. Ivan nods yes, causing Derpy to jump up and squeal in happiness. She eats the rest of her muffin as Ivan takes off his clothes. Derpy grabbed the box and placed it on the couch. She lays her front body on the couch, with her plump rump facing Ivan.
"Well, that explains where that went to," Ivan says, standing up and looking down at his foot-long dick. Derpy looks back at him, or more specifically his dick. Her eyes widen as her smile does the same. Her wings spread out at the sight of his dick.
"Hold on," Derpy says, grabbing three muffins and somehow eating all in one gulp. Ivan looks over to see Derpy's plot grow. Her eyes roll back into her head as she lets out a happy moan. Her plot plumps and grows to twice its original size.
"Dam, you plot is almost the same size as Celestia's," Ivan says, walking up to Dery and grazing his hand against her bubbly butt. Derpy lets out a happy moan at the touch as Ivan's hands sink into her rump. He massages gently, feeling the plush and muscles in her rump.
"Would you like it bigger?" Derpy asks, looking back at Ivan.
"If you want it?" Ivan says, squeezing her butt a little harder. Derpy shivers from the warm sensation of his hand. Derpy smiles and grabs two more muffins and eats them down the same way as the other three. She swallows as her tongue hangs out and a big smile forms across her face. Her butt blots and plumps up as her body grows slightly to stay in a somewhat normal proportion to her bubble butt. Her rump pushes against Ivan's dick, sliding against it and causing him to shiver in pleaser. She now stood hip height to Ivan with a huge plot spanning past his waist.
"Looks like somepony needs some help relieving themself," Ivan says, brushing her tail out of the way to see her dripping slit leaking pre-cum. He grips both sides of her butt and squeezes, sinking his hands deep into her plum, squishy plot. Derpy shivers and moans before replying back.
"Please fuck me." Ivan smiles and lines up his dick with her bubble butt. He slides the tip of his dick just inside her slit. The two moan at the same time. Derpy's slit grabs around his dick like a vise.
"I think you need more plush if I'm going to fuck you," Ivan says. Derpy looks back at him and the two smile at each other. Derpy grabs five more muffins and throughs them into her mouth. She swallows them as the magic starts to take over again.
Derpy shivers and twitch as her butt starts to grow. Ivan slowly pushes into her as her butt grows and pushes against him. Her body starts to grow as her rump gets even wider. Her moans are loud and happy as the magic keeps her growing. She is now almost three times bigger than when she started. Ivan is now having a hard time holding onto her hug plump rump. He massages it and squeezes it, causing Derpy to moan and give more cum to slip his dick into her. Her butt stops growing at the same time as Ivan is hip-deep into Derpy's slit and almost surrounded by her bubble giant butt.
"Ready my muffin mare?" Ivan asks as he squeezes her rump. She lets out a moan before nodding her head yes. She then gets an idea as Ivan pulls out of her. She grabs the box and places it in front of her. She eats a muffin as Ivan thrusts into her, causing her rump to giggle from the force. She chocks on the muffin from surprise and pleaser. She then swallowed it.
Her butt starts to grow as Ivan pulls out. She goes to eat another as she moans from Ivan's hands massaging her growing rump. She swallows another before Ivan thrusts again. Her eyes twitch as the pleaser of her grows and his dick pushing against her inside starts to overwhelm her. Her body starts to grow as her butt continues to plump up. She moans and shivers as Ivan grunts in pleaser.
He massages her growing up, almost hugging it at this point as he keeps thrusting into her. Derpy grabs two muffins and places one on her back as Ivan pulls out. He sees it and smiles at her. He grabs it and the two eat their muffins. Ivan sighs as he thrust into her tightening slit. His dick grew thicker inside of her. She melts into the couch as she feels his hands massage her flank as his dick pushes against her walls. His dick filled up every inch of her insides. Ivan relishing in her slit griping his dick and the wonderful rump Derpy has. Her rump keeps growing, now much wider than Ivan.
"Derpy, I can't hold it anymore," Ivan says as he thrusts one more time into her. He slumps against her back as he lets out cum into her. He instinctively does smaller thrusts into her as Derpy metals into the couch as she feels his warm body and cum. The two lay there trying to slow down their hearts from the impromptu sex session.
Ivan pulls out and claims on top of Derpy. He turns around and rests his head on her giant rump. "Let's take a nap, then figure a way to get your back to normal," Ivan says sleepily. Derpy chuckles, causing her rump to giggle before the two go to sleep.
