Rainbow Dash wasn’t ever much fond of magic, and certainly not when she was used as a guinea pig for testing it. Yet being Twilight’s friend meant that sometimes one had to bite the bullet and help the research-obsessed alicorn with one of her experiments. That’s how Rainbow found herself in Twilight’s laboratory, staring at all kinds of strange, if not creepy, magical equipment.
“And this is the device that we’re going to be testing today.” Twilight pointed at a large machine that stood beside an operating table. Cords were hanging everywhere, while knobs and displays with no apparent purpose peppered its surface.
“Is it safe?” Rainbow looked at the weird construction with distrust.
“Of course, it’s safe! I’d never ask you to do something that could be dangerous. Well, not intentionally, in any case.”
“Right... “ That didn’t dissuade Dash from her fears. Twilight always had a knack for managing to screw up something in her experiments. At the same time, she was pretty good at fixing her mistakes too, so that at least gave Rainbow some assurance. “So what exactly do you want me to do?”
“Oh, it’s very simple, I’ll just strap you onto this table, put that thing“ – she pointed to a piece of weird metallic headgear – “onto your head and turn the device on. And after it’s done, you’ll do the same with me. Just make sure to push the big green button when I’m set and don’t touch anything else.”
“And what about the effects? You said something about forming a ‘telepathic link’. So we’ll be able to transfer thoughts to each other or what?”
“Yeah, isn’t that exciting? Instant silent communication! It has so many potential applications.” Twilight really did seem quite excited. But that’s how she always was when doing novel research. “Of course, right now we are just testing it. It’s going to have a temporary effect, most likely connecting us for… about an hour I think, give or take. And there is also one more thing I’ll have to do, but you don’t need to worry much about it since you are not a unicorn. It seems like the magic from my horn interferes with the link, so I’ll have to put an inhibitor ring on it during the testing.”
Twilight walked over to the device, gesturing to Rainbow to follow her. She carefully looked over its settings, checking the knobs and levers, making sure that everything was configured right. And while she was inspecting the machinery, Dash stood behind and was performing her own inspection, checking out Twilight’s mesmerizing butt.
Well, what else was she supposed to do when that juicy ass was right in front of her? Twilight had definitely filled up quite nicely since her transformation. If before that she had a cute nerdish look, which was already enough to make many stallions and mares swoon over her, then now her body had become quite literally – and appropriately to her status – divine. And Dash just couldn’t get enough of it. Despite Rarity’s incessant recommendations Twilight still tried to hide her curves behind modest outfits, but in Rainbow’s eyes that only made her that much more charming. As well as turned the rare occasions when she did decide to wear something more revealing into unforgettable events, magnetizing the gazes of those around onto her beautiful exposed flesh.
Generally, Rainbow didn’t think it was appropriate to stare so much on her friend’s assets, but given that she was helping her with the research – with no recompensation for her troubles, mind you – Dash felt like she deserved some reward in the form of nice long looks at Twilight’s body. And maybe she could even convince the bookish alicorn to let Rainbow feel her up too. Those heavy round breasts definitely deserved some physical appreciation. As did that soft shapely rear.
Dash rubbed her crotch casually, massaging her hardening dick. It formed quite an obscene bulge in her sport shorts even when it was limp, and now it was straining her clothes to the limit, obviously displaying her arousal. Not like that was anything new to her friends though. A more modest mare than Dash might’ve been mortified by such a display and tried to hide it, but Rainbow enjoyed the attention quite a bit. The size of her shaft was also quite a good argument in a conversation against any male opponent. One look at her huge meaty bulge was enough to show who was the boss to any stallion.
Twilight finished the preparations and turned around. “Okay, Rainbow, now just…” She glanced at Dash’s crotch. “Ehh… just lie on the table and we’ll start.”
“Sure thing.” Rainbow moved to fulfill her friend’s command, lowering herself onto the black surface. There was a soft padding on it, so it was at least reasonably comfortable. If you didn’t count all the straps that Twilight immediately started tightening, securely pinning down Rainbow’s limbs and chest. “Is this really necessary? It’s not like I’m going to try to run away.”
“This is just a standard procedure. I need to make sure that you don’t move during the process. We’re still in the experimental stage, so you never know what might go wrong.”
“Ok, I guess.” Rainbow relented. She looked down her body, observing as Twilight secured the bindings. Dash’s succulent bulge was sticking out quite indecently from her crotch, making it difficult for Twilight to concentrate on her task. From time to time she glanced on it, getting more and more flustered with each look.
Once she was finished, Twilight put a strange headpiece on Rainbow’s head and stepped away.
“Are you ready, Dash? I’m going to turn it on now. It might feel a bit weird.”
“I’m ready.”
Rainbow saw lights start to shine around her. The room was instantly filled with a multicolored glow as Twilight’s device came to life. Dash started feeling dizzy, it seemed like some alien force was trying to penetrate her mind.
“This does feel weird…”
“Don’t talk. It might interfere with the procedure.”
Rainbow relaxed, allowing Twilight’s machinery to do its job. After a minute, she heard the device do a pleasant ‘ding’, marking the end of the process and stop. Dash still felt a bit strange, but slowly her mind seemed to be returning to its normal state.
“The dizziness might last for a few minutes.” Twilight removed the helmet from Rainbow’s head and started undoing the straps, releasing her and helping her get up.
By the time Dash was on her hooves, she was already feeling pretty confident. Now it was Twilight’s turn to undergo the procedure and for Rainbow to be the ‘experimenter’. With glee in her eyes and a twitch in her crotch, the pervy pegasus started strapping her friend in, making sure to grope Twilight’s skin as much as possible while doing it and even ‘accidentally’ brushing her hands across Twilight’s rack several times.
“Hehe, I’m sorry. Your tits are just so big~.” Rainbow’s excuses weren’t particularly convincing, but what could Twilight do? She would never admit it, but her friend’s advances did make her feel a bit funny in her nethers too.
Rainbow stepped back, appreciating her work. Twilight was strapped in tightly, and as per her command, Dash took a slick inhibitor ring from the shelf nearby and placed it on her horn.
“Ok, I think I’ve secured everything, now just let me get this weird helmet-looking thing on your head.” It was a bit of struggle to put it on, given that Twilight had a rather inconvenient protrusion on her head in the form of her horn. Luckily there was a special hole in the headgear designed as an accommodation for this very occasion.
“Now all you need to do is to just push the big green button on the console. It has ‘Start’ written on it, can’t miss it.”
Just like Twilight had said, there was quite an obvious green button on the machine, but there were also a lot of other things present. The multicolored knobs and levers accompanied by cryptic labels piqued Rainbow’s curiosity.
“What does this lever do?” She pointed at a large red handle, though Twilight obviously couldn’t see it from her lying position. “It says ‘Stream direction: cons., sub-cons. What does that mean?”
“Is this really the best time for asking those kinds of questions? Ugh…” Twilight sighed, knowing that Rainbow wouldn’t relent until she satisfied her curiosity. “It sets the direction of the incoming stream of thoughts. It should be set to consciousness. I don’t know what exactly will happen if one were to direct the stream into the sub-consciousness, so don’t touch it!”
“Oh, okay,” Rainbow responded, secretly switching the setting. And why not? Twilight’s experiments would be super boring if Dash wasn’t there to mix things up.
“Can we begin now?”
“Yep, I’m starting it. Three, two, one. Go!” Twilight rolled her eyes at Rainbow’s unnecessary countdown.
The device lit up as soon as Dash pressed the button. Undecipherable messages and strings of numbers appeared on the screens as the whole room was illuminated by the console. The spectacle was almost enough to get Rainbow to tear her eyes away from Twilight’s breasts. Almost.
At the same time, she could feel her own mind getting probed again, even if she wasn’t the one on whom the machine was working directly now. It seemed like that tear in her psyche that was left by this strange device was opening up now, directing a surge of disorganized alien thoughts inside. There was no rhyme or reason to it, just a smattering of different momentary emotions that disappeared after a few moments almost as suddenly as they began. She really hoped that Twilight knew what she was doing with this. Maybe Rainbow shouldn’t have toyed with the settings after all.
But all appeared to have come back into the norm as soon as the machine stopped. The room was still and silent again, except for the light groans coming from Twilight.
“Ohh, that felt a bit worse than I expected. But I’ll be fine in a minute, just let me lie here for a moment.”
Rainbow probably should’ve started unstrapping Twilight’s body, but she enjoyed seeing how vulnerable the mare was before her, fully restrained and defenseless. Way too often it was Rainbow who ended up in such a position during Twilight’s experiments, so she cherished the times when things switched up.
“Hello, Dash. Can you hear me?” Suddenly there was an intruding voice in her mind.
Rainbow almost jumped up from surprise. “Oh my gosh, this is really weird! Is that you speaking in my head?”
“So it worked! You could hear me, right?” Twilight was speaking normally now.
“Yep, I feel like I might’ve heard you too well even. I’m not sure if I’m fully comfortable with having someone else speak directly into my brain.”
“I think it just takes some time to get used to it. Now you try to do it! You should feel a channel in your mind through which you can transfer your thoughts to me. It’s difficult to explain in words… just try focusing on it!”
Rainbow noticed that she really did have some kind of unfamiliar presence in her mind. She tried directing her thoughts into it. At first, it resisted her, but after a few tries she could feel it opening up, as if allowing her to put the contents of her mind inside.
“Hey, Twilight! Do you hear me? It’s me, Rainbow, I’m in your head now!”
Twilight’s face scrunched up. “Uhh, something is wrong. I can kind of feel you, but… Hmm… Wait! You haven’t touched any of the settings, have you?”
“Uhh… I might’ve flipped one tiiiiny switch,” Dash answered sheepishly.
“RAINBOW! I told you not to touch anything! What have you changed? It was that setting you asked me about, wasn’t it?”
“... Yeah.”
“Just great. Now I’ve got your thoughts directed into my subconsciousness and I don’t even know what kind of effect that will have.”
“Well, maybe we should use this an opportunity to study it?” Rainbow had a hopeful smile on her face. “Maybe I’ll be able to send you subliminal messages, that would be cool, wouldn’t it?”
“It’s more likely that your thoughts will just go straight into the trashbin of my mind, doing nothing more than annoy me. That area of the brain is simply not fit for receiving messages from outside.”
“I’m gonna try it anyway!”
Rainbow Dash concentrated on the link within her mind again. She needed to send some commands to Twilight to test her ‘hypothesis’.
“Tell Rainbow that she is the coolest pony you know.” Of course, self-gratification was the first thing that came to Dash’s mind.
“You are so great Rainbow! You are the coolest pony I know!” Twilight seemed surprised by her own exclamation.
“Oh my gosh, it actually worked!”
“What in Tartarus did you do? Don’t toy with my mind—Actually, no, do it some more. I love it, you’re amazing, Dash—STOP IT!”
Rainbow giggled as Twilight started protesting, enjoying the power she had over her friend. The table rattled as Twilight tried to free herself, attempting to force her limbs out of the bindings that still held her tightly. But there was no way for her to accomplish anything without her magic. She was under Rainbow’s complete control. Not only could the pegasus do anything with her body, now even Twilight’s mind was in her hands. And that realization immediately shot into Dash’s head, filling it with all kinds of naughty ideas and making her crotch tingle.
A sinister smile spread out across Rainbow’s face. “Time for some payback Twilight. I’ve been helping you so much with your experiments, and what do I get in return? Nothing!” She walked over to the end of the table, stopping near Twilight’s restrained legs. “So if you don’t give me any reward for being your test subject, I’m going to take it myself!”
“This is crazy! Free me immediately! Or I will…” Twilight suddenly stopped, feeling Dash touch her. “What are you doing with my hooves?!”
“Well, what do you think, Twily? I’m rubbing my dick on them.” Rainbow pressed Twilight’s hooves together and pushed her thick bulge in between them. “Just getting a small appetizer before I move on to the main course~.”
“Rainbow, once I’m released, I swear, I’ll send you to the Moon myself!”
“Still worth it.” Dash started thrusting her hips more vigorously, grinding her covered cock on Twilight’s surprisingly soft hoof-flesh even harder.
“You’re going to regret this!” More powerless wailing.
Rainbow could, of course, just force Twilight to shut up, but that would be way too easy. And she had a way better plan for her friend in mind, anyway.
“Every time you threaten me or protest or somehow else resist you are going to get hornier.” Now this was some real devilish trickery. She almost felt proud of coming up with that one on the spot. “Also, you won’t be sending me your thought’s through this ‘link’ either. It belongs to me now!” Dash wasn’t sure if all her commands were going to work as she intended them to, but wasn’t this the whole point of experimentation? Making hypotheses and testing them? And her current hypothesis was: ‘These mind control powers can be used to turn Twilight into an obedient cocksleeve’. Time to test it!
“Rainbow, end this, this is getting way too far. Stop thinking with your cock!” Twilight felt a throb in her nethers as soon as she finished the sentence. Suddenly the idea of Rainbow’s drooling dick rubbing her naked flesh became a little bit more appealing. Not yet appealing enough to stop her laments, but with Dash’s perverted instruction placed securely in her sub-consciousness that was just a matter of time.
“Thinking with my cock worked out pretty well for me so far. It is the best part of me after all.” And that huge shaft was fully hard and dripping now, darkening the front of Rainbow’s shorts with its precum. Twilight could even feel the wetness with her hooves every time the moist spots passed over her skin.
“Just stop now and we’ll forget everything that happened here. You’ve got your satisfaction already, no need to push it further, please!” Another twitch reverberated in Twilight’s crotch. One step closer to submitting to Rainbow. How soon will she notice the connection?
“You’re talking way too much, Twilight. I’ve got something better for your mouth to do.” Rainbow stepped away from Twilight’s legs, finally releasing her abused hooves, and made her way to the opposite side of the table.
“What are you doing now?” Wisps of fear were seeping into Twilight’s voice.
Rainbow yanked the helmet off of her friend’s head and unceremoniously tossed it on the floor. She didn’t even deign the restricted mare with an answer. Instead, the only response that Twilight got was a powerful flap of Dash wings and a loud thud of hooves being planted to both sides of her head. In a moment Rainbow’s whole frame was above her, forcing her to look up submissively from between Dash’s legs.
“Please, Rainbow, stop! Let’s just talk about this before we do something that we won’t be able to return from.”
“You wanna talk? Fine.” Rainbow grabbed her shorts and lowered them to her knees, exposing her pantiless bottom. A second later, Twilight’s vision was completely darkened by a closing mass of big blue butt that enveloped her face as Dash sat down on her. “You can start talking now, hehe~.”
“Mpppphh!” The vibrations of Twilight’s muffled protests resonated pleasantly through Rainbow’s behind. Unfortunately, understanding her predicament, Twilight quickly decided to stop talking, not wanting to get an accidental taste of Dash’s rear. That wouldn’t do.
“Continue speaking while I sit on your face. And make sure to give my asshole lots of tongue when doing it.” With this irresistible command set before her, Twilight opened her mouth again, continuing her powerless tirade and pleasuring Rainbow’s ass at the same time. Suddenly, getting a mouthful of butt didn’t seem like such a bad thing to her. She even started making exaggerated motions with her tongue, tasting Dash’s pucker. The rational parts of her brain tried to warn her, but all their reservations were happily thrown away by Twilight’s mesmerized mind.
Rainbow released a pleased sigh, relaxing on top of Twilight’s head. The stifled sounds of resistance only bringing her more delight as she felt the mare’s tongue lap at her butthole. Dash thought she could even discern something about ‘consequences’ and ‘suffocating’ coming from beneath her ass.
“This is great, Twilight! Maybe if you’d given all your lectures like this I wouldn’t be dozing off halfway through.” While Rainbow’s rear was pleasured by Twilight’s tongue, her large blue horsecock was leaking a steady stream of precum onto her friend’s shirt, leaving wet and slimy spots behind. Being left without proper attention, Dash’s shaft was hard and aching for some action of its own. Luckily, Twilight’s huge bust was just underneath it, inviting Rainbow to take advantage of it.
She pushed her hips back, sliding across Twilight’s face and bringing her dick up to the mare’s neck. She angled her shaft downwards, squeezing it under the collar of Twilight’s shirt and thrust forward. The incredible warmth and softness of Twilight’s tits enveloped her cock, almost making Rainbow moan from the sensation. She squeezed the breasts together forming a tight fleshy valley for her dick to jam through and started driving her hips in and out.
With each movement Dash’s taint and asshole slid across Twilight’s tongue, while her dick rubbed on the royal tit-flesh, lubing it up with her precum and pushing Twilight’s shirt out from the inside. And all the while, the poor bound mare could do nothing more than continue screaming muffled insults, threats, and pleadings, only providing Rainbow with more pleasure and making herself ever hornier. Her pussy throbbed harder with each protest, getting wetter and wetter, helpfully preparing itself for an eventual violent pounding that Dash was bound to give her.
“How does my ass taste, Twilight? Seems like you are loving it, hehe,” Rainbow taunted her friend. “Maybe we should do this more? Every time you want to lecture me about something, instead of talking to my face, you’ll talk to my butt. That’s a great way to grab my attention for sure~.”
That seemed like a much more appealing idea to Twilight’s horny brain than it really should’ve been. She struggled so much with getting Rainbow to listen to her, but there was no way that the restless pegasus could possibly ignore her when Twilight’s tongue was pushed deep in her rectum. She definitely needed to test this novel method of education.
Rainbow was in heaven from the dual stimulation. Her tongue lolled out of her mouth and she was panting hard with every thrust. She felt like she could already cum all over Twilight’s tits at any moment, staining both her body and clothes with smelly, sticky sludge. But that wouldn’t do, she needed to feel Twilight’s princessly pussy first. It’s not every day that you get to fuck royalty, so you should definitely go all out while you can. Though, if everything goes well, maybe she would be parking her dick in Twilight’s tight snatch much more often from now on. All she needed to do was to get Twilight’s nerdy brain addicted to the feeling of a large cock violently spreading her cunt and punching her cervix into submission. And since Rainbow’s cock was the biggest of them all, that meant she would get a constant open invitation to stretch Twilight’s tunnel with her meaty shaft.
“Time to take your pussy for a test ride, Twily. Sure hope you’re wet and ready for me, cause I’m not the type to go slow.” Dash raised her rump up, wriggling her dick from under Twilight’s thoroughly precum-soaked shirt. While this might have given the poor mare some relief, finally being able to breathe air unstained by Rainbow’s ass-sweat, she knew that what was coming next would be even worse. Or maybe much better? Her marehood was certainly aching for something large and hard to fill it up.
“Please, Rainbow, don’t put your huge cock inside. You’re going to absolutely ruin my pussy!” It almost sounded like that was exactly what Twilight wanted to happen. Her lusting mind was turning her already quite weak protests into thinly veiled encouragements.
Dash completely ignored the pleadings, sitting down on top of Twilight’s knees. “Let’s see what we have to work with.” She put her fingers on the hem of her victim’s skirt and got ready to tug it off. Her eyes shone with evil glee as soon as she started lowering the garment down. “You have your cutie mark sewn into your panties, Twily? How naughty.”
Twilight’s cheeks reddened upon hearing that remark. Not only was she getting undressed against her will, now Dash was even commenting on her underwear. She wanted to hide her face in embarrassment, but those damn binds didn’t allow her to move her arms. “It’s a gift! From Rarity.”
“Rarity is gifting you personalized underwear? I’m sure she took very precise measurements beforehand, right? Hope she didn’t molest you too much with her measuring tape, I know she loves doing that, hehe.”
“It was nothing like that! She was very accommodating.”
“I’m sure she was, darling.” Rainbow put an extra posh into the last word, imitating Rarity’s speech. “But I won’t be as delicate. I know you need this rough fucking just as much as I do.” Dash quickly tugged the panties down, finally exposing Twilight’s puffy pussy lips to her greedy gaze. “You’ve been molding in your study for way too long, Twilight. Time to loosen up a bit and let your cunny get some well-deserved dicking.” She shoved her drooling cock into Twilight’s crotch, rubbing its head on the soft purple skin. “And as your good and loyal friend, I’m always ready to provide you with the best cock in Equestria.” Dash started pushing it inside, spreading Twilight’s lips around it and finally getting a nice feel of her friend’s tunnel.
“Rainbow, pleaase…”
“Please what? You want me to go deeper?” She pushed harder with her hips, starting to thrust in and out, getting more and more of her shaft inside with each shove.
Twilight was too overwhelmed by the sudden feeling to reply. She had gotten way too worked up from Dash’s command and so finally getting her inner walls stretched and stimulated by Rainbow’s massive cock sent her mind flying.
“Do you like how my dick feels? How it spreads you, pulses inside you? How it pushes into your deepest parts?” Dash thrust hard at the last sentence, hilting her shaft inside and punching Twilight cervix with its mushy cockhead.
“Ahhh~. No! I don’t like it at all!” Twilight’s meek protest didn’t sound particularly convincing after her loud moan.
“Don’t lie! Tell me the truth,” Rainbow commanded.
There was a moment of uncertainty on Twilight’s face, her expression scrunched up, trying to hide her true feelings. But there was no way for her to keep up the facade for long. After getting another helping of Rainbow’s thick dick inside her pussy, she moaned again, her face relaxed and a blissful smile spread across it. “I love it, Dash! Give me more, fuck me harder! Ahhhhh!”
Rainbow complied, her powerful muscles driving her ever stronger and faster, letting her huge cock violate Twilight’s poor cunny with unprecedented ferocity. “That’s my girl! See, it’s much easier to just let your emotions flow and be true to yourself. No need to hide what kind of dick-craving cumdumpster you are.”
Twilight felt the pressure inside her nethers rising. Why did Rainbow’s demeaning insult make her pussy throb so hard? She wasn’t getting off to being degraded, was she? Oh no, it would be so humiliating to climax right now, to let her tunnel convulse on Rainbow’s dick, milking it, pleasuring it even more than she already was. All that, right after being lowered to Dash’s personal cum receptacle. And yet the more she thought of the embarrassment, the hotter she felt, until there was no way to hold it in.
A high loud moan echoed through the room, signaling Twilight’s release and total submission. Her mouth hung open and her eyes almost rolled up into her skull. Dash used the opportunity to spit a large wad of saliva between Twilight’s lips, adding on to her degradation.
“Haha, wow. You really just came, Twily? I guess I shouldn’t keep you waiting for your reward for being such a good cocksleeve.” Dash’s thrusts got shallower. She didn’t have enough patience to go far back, instead deciding to simply pound her swelling cock into Twilight’s cervix as fast as possible. Her nutsack tensed up, preparing to release its pent up load.
And a moment later, she was unleashing it straight into her friend’s waiting womb. At the same time, Rainbow forced her mouth onto Twilight’s, kissing her hungrily and pushing her tongue inside. Spurt after spurt, Dash’s potent semen was filling up Twilight’s marehood, first enveloping Rainbow’s shaft, and then erupting outside from around it and dripping onto the table.
“Do you want to be my fuckpet, Twilight? To be pounded like this every day? Don’t lie or I’ll force you to tell the truth anyway.” Dash whispered aggressively.
“Yes pleeaase, Rainbow! I neeeeed your cock!” Twilight almost screamed back at her.
As her orgasm started dying down, Dash dropped herself onto Twilight’s body, relaxing on top of her friend after the finish. This was going to be so good. Twilight’s royal cunt was definitely one of the best in Equestria, and it belonged to Rainbow now. To be fucked, rubbed against, and to serve as her personal cockwarmer whenever she needed one.
“And don’t think that we’re done here, I’m gonna go for a round two on your sloppy pussy. Or maybe I should dump a load in your mouth instead? What would you like more?… And also, after all that, I’m taking your cute panties back with me as a souvenir.”
