Author's Note

This chapter was a bit shorter than the previous few. However, the chapter coming up next will probably be the biggest of them all. So there's that to look forward to.

Contains: Futa, along with the usual expansion/mind-control fetishes.

Growing Influence

“What are you saying, Twilight?”

Twilight sighed. She had called all of her other friends together to discuss what was going on with Rainbow Dash, but explaining her current theory wasn’t very easy.

“I’m not sure what I’m saying, but...something seriously wrong is happening with her. Surely the rest of you have noticed the way she’s been acting? Not to mention the..uhh..growth spurt she’s had.”

“Twilight’s right,” Applejack chimed in, “I saw her at the gym the other day. She came out of the back room after having a tumble with Thunderlane of all people. Those two never get along, and now they’re rolling in the hay? Doesn’t add up.”

“Maybe she’s having a second puberty!” Pinkie exclaimed.

“That..that’s not possib-nevermind,” Twilight shook her head, “I might know what’s causing this. When she came to visit me last, she had an amulet around her neck. I’ve never seen it before, so it’s possible she might have gotten it during her last trip with Daring Do”

“We should contact her right away then,” Rarity stated with an affirmative nod.

“Agreed. In the meantime, keep your eyes open. Rainbow seems to have gained some kind of ability to entrance people, so don’t let yourself be caught alone with her if you can avoid. If you see her, call someone.”

“Oh my..is she becoming dangerous?” Fluttershy asked.

“Thankfully, no. At-least I don’t think so. All she’s done so far is seduce people. It’s her own well being I’m more concerned with right now.”

“Don’t worry, Twi. Whenever she comes back to Ponyville, we’ll catch her,” Applejack replied. Meanwhile, Pinkie was already working on assembling some sort of elaborate trap in the background.

“Alright, we’ll meet back up as soon as someone locates her. Good luck, girls.”

Rainbow Dash narrowed her eyes at her phone as she made her way back to Ponyville. There were several messages from her friends, all asking her to meet with them to discuss what was going on.

“They’re onto you. You must find a way to distract them” said a strangely familiar voice in her mind.

She paused and tried to think what she could do. Twilight likely wouldn’t let her guard down a second time, so entrancing her again was out of the question. She needed to get at least one of her friends over on her side, one that would fall under her charms quickly and without too much resistance. A smile crossed her face as she selected her target.

“Fluttershy”

Dash quickly began to make her way through Ponyville, receiving no shortage of stares as she went. As she examined herself it wasn’t hard to see why. Her little affair with Soarin seemed to have fueled the amulet into giving her another growth spurt. Her breasts were bulging out of her shirt and bra, and her skirt failed pitifully at stopping part of her jiggling ass from being exposed here and there. At the rate she was growing, it wouldn’t be long before she reached the proportions she had in the dream. She needed to take care of things here and move on to the temple fast. Soarin had already arranged for a private plane to take her to the destination, but she needed to make sure her friends wouldn’t try to follow her.

After exiting town she headed straight for Fluttershy’s college, hoping that she’d be able to catch her friend alone. Her wishes turned out to be a reality, as when she approached she could see Fluttershy tending to her animals outside before going back into her home. Rainbow Dash smiled and quickly moved in. As she approached the door she began fantasizing about all the ways she could go about this. She could hypnotize Fluttershy into a stupor with her huge, bouncy breasts. She could have Fluttershy pound her fat flank with a strap-on. Or maybe she’d just go to town on Fluttershy’s marehood and give her the biggest orgasm of a lifetime.

As she approached the unlocked door, a small bit of doubt went through her mind. It was like the various doubts she had been having all along, but the feeling was steadily getting weaker. Why listen to those annoying thoughts telling her to stop when she was having so much fun?

“What’s there to feel guilty about? It’s not like I’m going to hurt her. I’m just gonna show her how to really enjoy herself, and then have her repay me with a small favor”

She pushed the door aside along with her doubts and entered the cottage. After a quick search, she found Fluttershy in her pantry.

“Hey there, Fluttershy!”

Fluttershy gasped in surprise and turned around, “Oh my, it’s just you Rainbow Da- WAIT! Oh no!” She quickly reached into her pocket and pulled out her cell phone, but before she could dial Rainbow Dash grabbed her by the wrist and tried to slowly wrestle the phone away.

“Whoa there, just put that down. I only want to talk and show you a few things~” She looked Fluttershy straight in the eyes, giving her a powerful and alluring gaze that quickly caught the other woman’s attention. Fluttershy blushed nervously as she tried to regain control of the situation, but she found herself starting to be overcome by some station power washing over her mind.

“Come on, Flutters. Just listen to Dashie and drop the phone. It’s time you and I had a little bit of fun together~” Rainbow cooed. She held on to one of Fluttershy’s wrists with one hand while reaching her other hand down her friend’s skirt, and then past her silky panties. Dash then started to gently rub Fluttershy’s marehood before slowly fingering her with one digit. Fluttershy blushed even deeper and let out a light moan in response.

“R-Rainbow Dash..s-stop...we...we need to get the others..a-and..”

“But if you call the others, you’ll miss out on the chance to check out this rockin new body of mine,” Rainbow replied before shoving Fluttershy’s face right into her mountain of cleavage. Fluttershy let out a muffled cry as a pair of giant blue tits consumed her entire range of vision. She struggled at first but soon found herself overwhelmed with an instinctive urge to start groping Dash’s breasts. Her hands slowly rose up and wrapped around the two fleshy orbs before squeezing eagerly.

“Mmmh, that’s more like it. Just indulge yourself,” Rainbow Dash was practically purring as Fluttershy eagerly groped and massaged her breasts. She then moved her hands down and traced the curve of Dash’s hips before groping at the huge expanse of her backside.

“My goodness, Rainbow Dash. Such curves you’ve gotten. I think your boobs might be even bigger than mine now.”

“Hmm. Let’s test then, huh? Take off your shirt and bra,” Dash commanded.

Fluttershy immediately begin to do as she was told, feeling almost instinctively obliged to obey what her friend was telling her. She quickly took off her shirt before unsnapping her bra, letting her own voluptuous breasts bounce free. Meanwhile, Dash stripped off her own top as well. She then moved in and pushed her heavy breasts against Fluttershy’s. Blue and yellow tit flesh squished together erotically as they compressed their jugs against one another. Both women moaned as their nipples made contact. After getting properly lined up, it became clear that Dash was definitely the bustier of the two now. It wasn’t by much, but it was definitely noticeable. Fluttershy usually wore a G-Cup bra, which meant Dash was now a cup size or two beyond that.

Both mares blushed, with Fluttershy blinking in astonishment, “A-Amazing. S-So how’s it feel to be in the top-heavy club?” Fluttershy giggled.

“It feels great actually. But I don’t want you to feel left out. So I’ve decided to give you something special. Something that will be big fun for the both of us.”

“O-Oh?”

“Just hold still,” Rainbow smirked as she kneeled and pulled down Fluttershy’s skirt and panties. Her friend let out a surprised “eep” but kept in place as commanded. She began to slowly rub Fluttershy’s tiny clit between two of her fingers. Fluttershy moaned loudly and passionately, while Dash just smiled knowingly. Soon the sensations for Fluttershy began to intensify, her clit engorged further and further. A few moments later she realized it was actually getting larger. Rainbow Dash’s smirk grew wider as they both watched Fluttershy’s clit becoming thicker and more lengthy by the second. Dash soon began to rub it with three fingers, and then four, grasping more in her hand as Fluttershy’s clit was now protruding to a ludicrous size. It then began to change in overall shape, a thick ring formed around the middle of her clit, while at the end of her feminine rod a type of head began to form. It was then that Fluttershy realized Rainbow Dash was making her grow a cock.

“R-Rainbow...this...it feels so strange, it’s almost too much”

“Shhh, it’ll be alright. I promise you’ll enjoy it when I’m done,” Dash replied calmly as Fluttershy’s change continued. While Shy’s clit continued to become more and more penis-like, an extra sack of flesh was being formed at the hilt of her rod. Inside that sack were two small testicles that quickly began to grow in size along with their container. Within just a few moments Fluttershy was sporting a fully functioning male shaft, along with a pair of balls bigger than most guys could hope to have.

“Dash..did you just give me…”

Rainbow Dash nodded, “Indeed I did. Consider it an early birthday present. I’ll get rid of it when we’re done if you really don’t want it, but I think you’ll decide it’s a nice addition~” She then leaned forward and began to lick at the head of Fluttershy’s new member. Fluttershy moaned in surprise as her strange appendage throbbed in response. Dash skillfully went to work, gently massaging Fluttershy’s balls while beginning to lightly suck on the first few inches of her rod.

“O-h my..it’s s-so sensitive...I’ve n-never felt anything like this…so this is what it’s like for the males.”

Dash let out a muffled response while taking a few more inches of shaft into her mouth and sucking faster than before. Fluttershy could only groan helplessly, the foreign sensations overwhelming her body as her knees became weak. Just when she thought she couldn’t take anymore, Rainbow relented the assault.

“So, how do you like it so far?” Rainbow Dash asked with a giggle.

Fluttershy blushed heavily, her rod still throbbing powerfully “I-It’s different..but it feels sooo good. C-Can we do more?”

Dash smirked, “Well, I’d be a pretty poor friend to give you a new tool like that and not help you try it out. I have the perfect idea, just sit down and get comfortable.”

Fluttershy did as ordered, sitting down in one of the dining room chairs and looking at her friend expectantly. Rainbow sauntered over and leaned down before heaving her massive breasts into her friend’s lap. With a bit of effort, Dash managed to get Fluttershy’s cock nestled away in her expansive cleavage. Only about a third of Fluttershy’s member was visible, the rest was encased by beautiful blue tit flesh. Having previously practiced this on Soarin, Rainbow Dash was now able to move her boobs up and down far more smoothly. She used the heavy orbs on her chest to pleasure Fluttershy very skillfully and efficiently.

“Oooooh..R-Rainbow Dash..y-you’re boobs...they’re so big and soft…”

Rainbow Dash smirked, “I’m glad you like them. You can play with them all you want from now on~” She began to quicken her pace, moving her breasts up and down faster than before. It was a bit harder to keep up this time, as her girls had gotten heavier since she performed on Soarin. If they got much larger, it could get tough to pull off this kind of sexual act. However, it was hard to deny how much pride it gave her to see her massive bust filling out Fluttershy’s lap almost entirely.

Fluttershy’s moans only got louder as Rainbow’s tantalizing breasts worked to push her closer and closer to the edge. Her member throbbed more rapidly than before, and she could feel her balls beginning to tighten. The pressure was about to reach its peak when Dash began to slow down.

“N-No...please, don’t s-stop. I need more!”

Dash smirked, “I’m not sure you want it enough”

“I-I do! Please, Rainbow Dash...I gotta c-cum!”

That was enough to get Rainbow Dash back to work, satisfied at how easily she was breaking Fluttershy in. “Look at you, Flutters. Begging to cum like a dirty futa-slut. I bet this new rod is going to get a lot of use.”

Fluttershy nodded, babbling as Rainbow Dash pushed her breasts together tighter and tighter. “S-so goooood”

“Alright, Flutters. I hope you’re ready to blow your first load!” Dash exclaimed as she put her all into it.

Just a few seconds after Fluttershy let out a loud cry of pleasure as she began to splatter heavy goops of seed all over Dash’s breasts. One wave came after another as the newborn futa unleashed copious amounts of cum out of her shaft. Rainbow eagerly encouraged Fluttershy to pump out as much as possible, continuing to use her breasts to massage her friend’s unloading cock.

Fluttershy panted heavily as she finally emptied out the last of her seed, “Oh gosh...Rainbow Dash...I’ve never felt like that before…”

Rainbow Dash smirked, “Heh, this is just the start. You ready for round 2?”

Fluttershy shook her head, “I..I can’t...I don’t think there’s any le-”

Fluttershy’s protests were interrupted as Rainbow Dash began to massage her balls with both hands. There was some kind of energy in Dash’s grip, as Fluttershy could soon feel her testicles swelling heavily with cum all over again. By the time Rainbow had finished her work, Fluttershy’s balls had swollen slightly larger than they were before. Meanwhile, Fluttershy found her sexual vigor being restored as well, with her cock already throbbing back to life.

“How about now?” Dash asked with a smirk as she went down on all fours and wiggled her fat rear at Fluttershy. Her marehood dripped heavily with wetness, practically inviting Fluttershy to stick her member in and start pounding away. Rainbow Dash pushed her hair back and gazed enticingly at Fluttershy over her shoulder. Fluttershy couldn’t help but feel pulled into her friend’s lusty gaze and began to stand up and walk forward out of her own control. As if by pure instinct she began to line her member up with Dash’s entrance, gently applying pressure as she prepared to penetrate.

“That’s right, Flutters. Just do what comes naturally~” Dash replied, her own body tingling with anticipation. Said anticipation was finally satisfied when Fluttershy began to gently push her rod into Rainbow Dash’s folds. Both women moaned openly with pleasure as Fluttershy pushed into her friend’s depths inch by inch. After finally bottoming out, Fluttershy slowly withdrew from Dash’s marehood only to plunge right back in. Her thrusts were shaky and weak at first, but she soon began to find a steady groove as she pounded away at Rainbow’s cunt.

Rainbow Dash’s moans became louder as Fluttershy took a tight grip of her hips and began thrusting with increased vigor. It was impressive how quickly she was getting used to her new tool. Dash decided to give her plenty of encouragement, pushing her heavy hips back against Fluttershy. She gasped with surprise as she felt Fluttershy slap a hand against her right flank cheek.

“Mmmh..your body is so amazing, Rainbow Dash. I can’t believe how big and soft your flank is,” Fluttershy cooed as she squeezed and groped the huge, rounded cheeks of Dash’s backside. The way Dash’s ass bounced and jiggled with every impact was driving Fluttershy purely wild. Everything about her friend now seemed designed to draw her in. The wobbling of her backside, the heavy sway and bouncing of her massive breasts, the dazzling passion in her eyes. She’d do anything Dash said if it meant they could repeat this day.

“Keep it *pant* up, Fluttershy...you’re doing awesome,” Dash encouraged as she eagerly took the rutting that Fluttershy was giving to her. Already the amulet around her neck was beginning to glow with the energy provided by all the lust in the room. She was amazed by just how intense this all was.

“Maybe I should make my other friends grow cocks too”

She pictured in her mind a scene where all five of her best friends had been transformed like Fluttershy, and how they all took turns having their way with her in several different positions. It all made her marehood even wetter than it already was, and just in time for Fluttershy to begin thrusting even harder and faster than before. Her friend was now pounding away at her marehood like a feral animal, showing no mercy as she rammed Dash’s pussy. The entire room was soon filled with the lewd slapping sounds of their hips colliding rapidly again and again.

“Unnnghh...R-Rainbow Dash...I don’t know how much longer I can hold it. You’re so warm and tight”

“J-Just keep going, Fluttershy. Don’t hold back!”

Dash could feel herself getting closer to the edge as well as Fluttershy continued to give her the pounding of a lifetime. Her flank was hit by several rough spanks before Fluttershy leaned down and began to grab and fondle her breasts as well. Now going full doggy style, Fluttershy thrust forward with reckless abandon, desperate to pump her friend’s womb full of futa sperm.

“D-Dash...I’m about to..” Fluttershy’s warning was accentuated by the heavy throbbing of her member, which combined with the flaring its head to signal to Rainbow Dash she was about to get inseminated.

Both friends moaned together as they pushed each other over the edge. Dash released her feminine juices as her marehood tightened around Fluttershy’s member, which responded by flooding her inner walls with thick spunk. Fluttershy tightly held onto Dash’s hips as she desperately thrust in and out, pumping out more seed every time.

Rainbow Dash panted and gasped with contentment as she felt her womb getting more and more filled by all of her friend’s new sperm. The amulet on her chest glowed heavily and sent a tingling of energy all throughout her body that was almost as pleasurable as the orgasm she just had. Finally, Fluttershy’s deluge came to an end and she pulled out. Rainbow collapsed to the floor for a few moments to catch her breath, while Fluttershy fell back in the nearest chair to do the same.

“Phew...wow, Fluttershy. I never knew you could be such an animal~” Dash complimented with a sultry smirk on her face.

“S-So..so amazing…” Fluttershy panted, both her voice and eyes having a “far out” nature to them now.

Rainbow Dash smirked, knowing she’d have Fluttershy under her total control for the time being. She stood up and walked over, looking her hypnotized friend in the eyes.

“Now that we’ve had our fun, I’ve got a really special favor to ask of you, Fluttershy.”

“Sure, Rainbow Dash. Anything you ask,” Fluttershy answered obediently.

“I need you to keep the rest of our friends distracted for awhile. Wait a few hours after I leave, then call and tell them you saw me heading into the Everfree forest. Got it?”

Fluttershy nodded blankly.

“Good girl. Once I take care of things, I’ll come back and we’ll have a lot more fun ahead of us~”

“Are you sure that’s where she was going, Fluttershy?” Twilight asked skeptically.

Fluttershy nodded, “I-I saw her walking towards the entrance. I tried to tell her to stop, but she didn’t listen to me. She just kept going..like she was drawn to it or something”

“Did she still have the amulet on her?” Applejack asked.

“Y-Yeah. She looked even more changed than last time…” Fluttershy’s mind wandered to Dash’s beautiful, bouncing tits and her fat, jiggling booty. She could feel the new “friend” coming to life under her skirt and quickly worked to cross her legs in a way that would hide it. She knew if her friends noticed the new addition to her body they’d figure out what really happened.

“We should follow her at once then,” Rarity said with concern.

Twilight shook her head, “No, it’s too dangerous. If we get caught alone with Dash she could entrance us. Daring Do is already on her way here, we’ll wait until she arrives and then we'll make a plan.”