Author's Note
SO. Here I am and here this is. This story had been in my "to do" list for a while so i figured id finally do it. Im not sure how it turned out since i wrote this story halfway at different time periods. Hah.. Its been a while sorry! 
Anyways i hope you enjoy non the less i tried to make this one more erotic than my other stories with the whole transformation thing. This is my first time trying to write anything of the sort so im not sure how i did.. Hope its good! (Does this story need the fetish tag? If so let me know and ill add it.)
As always. Feel free to tell me ways I can improve or things that are spelled incorrectly, all that jazz. (Be nice down there!) 
My Little Toy
"You do realize this is a bad idea, right?" Rainbow asked while her and Twilight sat behind a totally not suspicious bush. She was a little perplexed about there current situation. How Twilight, of all ponies, came up with this prank was beyond Rainbow. Maybe I'm rubbing off on her a little too much?.. Rainbow laughed at that thought. She was definitely rubbing off on Twilight, in more ways than one if she might add.
"What's so bad about it? I put a protective layer of magic around everything. She has nothing to be angry about!" Twilight exclaimed with a tinge of excitement, not taking her eyes off Rarity's boutique. Any minute now Rarity would walk in, her show room being covered in rainbows like it was Dash's bedroom as a filly.
Rainbow laughed at Twilights reasoning. "Can you please tell me why I agreed to you using rainbow paint of all colour combinations? Its going to be blatantly obvious that it was ME."
"Shhh!" Twilight quickly planted her hoof over Rainbow's mouth, but blushed a little when the cyan mare started licking her under hoof in retaliation. "Stop it you.. Look! Here she comes!" Twilight whispered. She was shaking on pure adrenalin. She rarely pranked her friends, usually leaving that to her mare friend and Pinkie. But when she did it really made her heart race!
"Do.. Do you think it worked?" Twilight asked curiously while peaking over the bush a little more to get a better view. Had it not worked? No explosion could be heard, not even a birds chirp..
"I think you might have planted a faulty paint bomb, Twi. Hey, on the bright side, at least we don't have to worry about her being ang—" Just as Rainbow began to speak, both her and Twilights ears perked as a small bang reverberated through the inside of Rarity's boutique. "Oh horse feathers..."
"RAINBOW DASH!!" A voice sounded from inside the white and now partially rainbow building. It was unmistakably Rarity's voice and she was not happy.
"Uh.. I think its time to go Twi!" Rainbow looked down only to watch her mare friend roll around on the ground in laughter, clutching her chest to stop the pain from laughing to much. For what this was worth, Rainbow had to admit that seeing Twilight being so cute was worth all the yelling she was going to receive from Rarity in the future.
With a small blush Rainbow quickly picked up the purple mare in her forelegs, with a little struggling from all of her wiggling about, and took to the skies. Seeing as how Twilight was clearly in no shape to fly now, she would have to take her home like the responsible mare friend she was.
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Landing on Twilights balcony, Rainbow slowly opened the door with her mouth and made her way over to Twilight's bed. Hopping on her hind legs she carefully set the sleeping mare down and covered her with the blankets. It was truly a beautiful sight to behold. This mare.. Her mare.. Rainbow truly considered herself the luckiest mare in Equestria.
Taking one last long glance at Twilight's face, as if making sure she could never forget it, Rainbow turned to leave the way she came. "MmnnDashie.. Where.. Do you think you're going..?" Came a groggy voice from behind her.
"I.. Was just making sure the door was locked?" Rainbow spoke lowly. She didn't want to wake Twilight anymore than she was already. The mare was tired enough as is.
"You better not be leaving me.." Twilight quietly responded.
Those words made a shiver shoot up Rainbow's spine. That was never going to happen. Not while she lived. "Twi.." Rainbow spoke while making her way to Twilight's bedside again, positioning her head right above Twilights. "Ill never leave you."
Reaching up from under the covers Twilight snaked her forelegs around Rainbow's neck and pulled her down for a passionate kiss. For she secretly knew they were Rainbow's favorite kind of kiss.
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Slowly opening her sleep crusted eyes, Twilight quickly shut them again as the blinding light of Celestia's sun spewed its way through her balcony windows. Why were her curtains open in the first place? She always closed them before bed.. Turning onto her other side so she could actually see, Twilight's eyes widened as she saw none other than Rainbow, not sleeping, but standing by her bedside with a tray of what she could only presume was breakfast laying patiently on the bed in front of her. Her eyes went back and forth between the food and Rainbow's eyes. Why Rainbow made her breakfast in bed, she had no idea. Did Dash finally get accepted into the wonder bolts and there was a hidden note in the oatmeal? Or did she break something and now she was trying to make up for it?
"Morning Twi.. Have a good sleep?" Rainbow asked, unknowingly interrupting Twilight's thoughts.
Carefully sitting up as to not knock over any of Rainbow's presumably hard work, Twilight nodded in approval before grabbing the tray of food in her magic. Sure, something was fishy about all this, But she didn't have enough evidence to convict her of any 'crimes' yet. So instead she just sat back and enjoyed her labour free meal.
"That's good to hear." Twilight heard Rainbow say with a smile while fidgeting around in her spot. Twilight noticed that Dash's gaze was almost scarily fixed on her. Something was definitely up with her and there was no denying it. "Hey, u-uh, I have to go.. out for a bit. Is that alright?"
Twilight pondered on what to say, sure she could ask what Rainbow was up to, but with this first display of breakfast in bed. Did she even want to know? Dash would probably just play it off as nothing anyway.. ."Yes Rainbow, that is alright." Twilight spoke, trying her best to not sound suspicious and blow oatmeal all over her bed.
"Awesome! I'll be back before you know it!" Rainbow bolted forward and hovered over Twilight, giving her a kiss and a lick on the cheek.
Before long Twilight heard the front door to her library shut. "Oookay.. What was that?" Twilight spoke aloud to herself, half expecting an answer from some pony hiding under her bed. At this point she wouldn't be surprised. This was the weirdest she had ever seen Rainbow act. Her questions would need to be answered sooner or later or she was going to go insane. Shaking her head Twilight sat up and off of her bed, making of said bed would have to wait till later. Her mind was too jumbled to do anything right now.
Walking out of her bedroom Twilight looked at her front door and half expected Rainbow to be there, but no such pony was seen. Twilight sighed. Whether she was in for a trick or a treat, she was going to be prepared for it. Though before she could get not halfway down her stairs she was stopped by something she didn't quite expect. A book lay dormant in the middle of her staircase. What are you doing here? She thought to herself before picking it up in her magic and reading the title. Transformation magic 101? Twilight had no intellect of where this came from. She didn't keep magic studying book in the main part of her library, or at least she thought.
Reaching the bottom of the stairs she sat down at her study and flipped to the first page. Even if she had no recollection of how this came to be in her possession in the first place it surly wasn't the weirdest thing that has happened with her morning so far, so what the harm in a little read? Besides, this was a good way to pass the time until Rainbow got back so she could ask all her questions.
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Hearing the main door open to her library, Twilight peered up from the book and saw the mare she had been waiting for all evening. "Where exactly have you been?" Twilight asked while putting her attention back onto the now not so mysterious book.
Rainbow rubbed the back of her head with a hoof. "Sorry Twi, I got a little caught up helping Rarity clean her boutique after she saw me in the market. All because some pony used Rainbow paint."
"Hey! You-"
"-Started it, I know Twi, I'm just playing with you." Rainbow said with a smirk while making her way over to Twilight's side. "Whoa.. What's that?" Rainbow blurted out curiously and—before her mare friend could say something smart—grabbed the book from Twilights magical grip.
Playfully jabbing the Pegasus in the side, Twilight quickly sat up and grabbed the book in her magic. "N-nothing!" Twilight blabbered out while putting the book behind her, out of view from her mare friend. She could tell Dash what the book was all about, but there was a lot if interesting spells in it that could come in handy if she ever needed to get some sneaky revenge in a pinch.
"Hmm.. If you say so Twi." Rainbow asked before heading into the kitchen to get a glass of water. Though before entering said kitchen Dash stopped and smirked a little. "Hey Twi? Did you know there's a package outside for you?"
Twilight's eyes went wide as dinner plates as what Rainbow had said started to sink in. When did her package arrive? Did Rainbow see what was inside? She hadn't been outside all day thanks to this book she got sucked into. "Oh sweet Celestia.."
Rainbow watched as her mare friend bolted to and out the door. Everything was going exactly as planned and Twilight had no idea what she was up to. "Tonight's sure to be one for the books." Rainbow spoke to herself with a grin before entering Twilight's kitchen.
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Quickly shutting her door behind her, Twilight set the box down onto her bed and giggled like a school filly. She knew exactly what was in this box and she was hoping that Dash didn't go snooping around before telling her it had arrived. She had bought this for her after all.
Walking up to the box Twilight opened the top with her magic and stared at the contents inside. A dildo that Twilight had specially made, just for her and Rainbow. It required a special magic battery to work properly, but it was worth the cost of such a thing. The idea for this was the brainchild of a very heated night. Rainbow had suggested Twilight measure both of there vaginal "love tunnels" as Dash called them to see who's was deeper. As it turns out her and dash were almost the exact same in depth and thus.. Twilight attentively stared at the product before her now. Its measurements, if made correctly, were supposed to be snug fits for both of them. She could also change the size just in case a little punishment was in order and that was just scratching the surface at what this thing could do. Hearing a creek of her door, Twilight jumped out of her thoughts as Rainbow's voice echoes around her rooms walls.
"Sweet Luna, Twi!" Rainbow blurted out before bolting past her mare friend and picking up the dildo in her hooves. "Wh.. Where did you get this!" Pushing down on the tip with force Rainbow watched as it sprung back up, nearly hitting her right in the snout with just the tip.
Grabbing the toy out of Rainbows grasp, Twilight set it down back in the box. "That. Is for later, ok?" Feeling two hooves on her chest Twilight fell back onto the hardwood floor as a cyan pony pinned her forelegs in place on either side of her.
"Later huh?" Rainbow lowly spoke while leaning down to slowly lick and nip Twilights exposed neck. "Why." Rainbow started to nip at Twilights neck more assertively than before. "Not." Licking from Twilights throat up to her wet lips Rainbow groaned as she felt two wings rub against her own extended wings rather aggressively. "Now." In an instant Rainbow felt a pair of lips on hers. The purple alicorns tongue snaking its way into her mouth as she flipped them both over.
Pulling back from the kiss Twilight looked down on her comfy seat and grinned. She could feel herself leaking onto her mare friends as she slowly grinded her lower lips against Rainbows lower chest. She didn't know why or how she got so horny so fast, but she wasn't complaining. "Mmm Dashie.." Twilight watched as Rainbow grabbed onto her wings with her own, just like before. The feeling of purple feathers interweaving into cyan was one of pure ecstasy.
Rainbow felt and watched in awe as her mare friend slowly grinded herself off on top of her. Her wings slowly got more and more entwined into Twilights as she heard the mare atop her moan and grind more and more than before. It was a cycle of love that Rainbow was enjoying thoroughly. As Twilights moans got more high pitched and erratic Rainbow knew she was close to giving her a mini shower. Leaning up just enough to meet Twilights pleasure hung head halfway Rainbow nuzzled Twilights cheek in the most loving way possible. Dash smiled as she felt Twilight quickly returned the loving nuzzles. "Come for me Twi.. I know you want to come on me Twi.. Let it all mmn-!" Rainbows words got quickly cut off as Twilight kissed her passionately. The feeling of juices running down her cyan chest, sides and onto her exposed belly made it all to clear to Rainbow that Twilight had finished. "Out.." Rainbow spoke with a smile while nuzzling her mare friends cheek once again.
Twilight nuzzled Rainbow back once again as the afterglow of her orgasm slowly faded away. For some reason that had been one of the most intense orgasms she had ever had. Laying herself down from her current position, Twilight felt her juices squish between there belly's as she put her weight down onto Dash. "Mmm.. That was amazing Dashie."
Rainbow laughed as she softly bumped Twilights muzzle with her own."Heh.. All I did was supply the sweet talk and external pleasures. You did all the hard work Twi."
"Hmm.. I beg to differ." Twilight spoke with a grin as she stared into those magenta eyes.
"Please do." Rainbow said with a grin, staring back with the best bedroom eyes she could put on.
Lighting her horn Twilight grabbed the box that had been left forgotten and set it down beside them both. Pulling the toy out of the box once again, but this time to stay, Twilight watched as Rainbow's eyes went wide in realization. "Don't worry Dash.. I wont hurt you." Snaking her way down Rainbows body Twilight eventually came face to face with her glistening cyan slit. She couldn't help but give the beautiful lips a little experimental blow, just to see the reaction of course. To her total surprise she heard a small moan from up above her current position. Twilight giggled to herself as the legs on either side of her twitched in anticipation. Twilight never thought she would enjoy teasing, but the action was something she surprisingly enjoyed. Though now was no time for that. She knew how horny Rainbow must be after watching the show on top of her just moments ago.
Rubbing the tip of the fake stallion hood against the outer folds of Rainbows plump vagina, Twilight smiled warmly as the leg twitches grew in treble, an indication that she was doing what the mare wanted. Deciding to give her what she wanted, Twilight slowly penetrated Rainbows cavern with the first 5 inches. She half expected Rainbow to buck her legs back and give a loud moan of approval, but no such action or sound came. Shrugging, Twilight pushed the remaining inches into her lovers snug love tunnel until she bottomed out. Dash sure was taking this like a champ. Not even a single moan emanated from her mouth the entire time during penetration.
"Uh, Twi? A-are you going to.. Y'know.." Rainbow lifted her head up and looked at the mare between her legs with a curious, but desperate look.
Twilight looked at the dildo firmly lodged inside of the vagina before her, then up at Dash. She was thoroughly confused as to why Rainbow wasn't feeling any pleasure from this at all. Pulling the toy out of her mare friend Twilight looked it over and her eyes went wide in realization. "Oh please please please don't be what I think it is!" Opening the little compartment in the bottom of the toy, Twilight dropped the toy in her magic and fell to the ground in a mixture of shock, confusion and disbelief.
Rainbow shot up from her exposing position and sat next to Twilight. "What is it! Are you alright?"
"I-i'm fine, Its j-just.." Twilight sniffled as she lifted the toy up to Rainbow's view to look for herself. "T-The battery is gone! I-I had Cadence get one made just for this specific thing and t-there so expensive! If I lost it.. S-She's going to murder me!" Twilight hung her head down in shame as her concentration failed her, the toy falling once again to the ground below her.
Rainbow put her wing around her mare friends back and sucked in a breath at how sensitive they were. She almost forgot about the current physical education class they were having. "Hey.. Don't say that! I'm positive that it will show up soon enough, trust me." Rainbow smiled as she rubbed Twilight's back with her wing, making her moan under her breath.
Twilight curiously looked over at Dash before realizing she must be still incredibly horny. "Oh Dashie! I-i'm so sorry! I got so caught up with.. You must be going crazy!"
"Its fine Twi, really. I'd rather go to sleep wet than you go to sleep crying." Rainbow spoke with only truth in her voice. She hated seeing Twilight cry, it made her cry and Rainbow Dash did not cry. "So, why cant you power it with your own magic, what's so special about this battery?"
Twilight pondered the question. She herself didn't know fully as to what the battery did per say, but she knew why she needed it. "The battery has Princess Cadence's magic imbued into it. Since I got it special made Cadence had to do some special things to it in order to make sure it works. Magic that isn't tuned to her frequency of love like mine or Celestia's, no matter how powerful the magic, it wouldn't work properly. That's why she made me the battery. She knew the initial charge would run out on delivery here so she wanted to make sure we could.. Well, use it!" Twilight threw her forelegs up at that last part. Clearly they weren't going to use it tonight and she was looking forward to pleasuring Rainbow with it.
Rainbow looked away so her face was out of view of her mare friends gaze. Her smirk was cruel, but she couldn't help it. She knew Twilight was going to have a freak out session over losing the battery when she took it out of the box earlier, but she knew the last part of her plan was going to cheer her up, that was a promise. "H-hey Twi? What's this?" Rainbow asked as she grabbed the book Twilight had been reading while she was gone earlier today.
Twilight turned and looked at what Dash had found, half hoping for it to be the battery, but instead it was just the book she had been-.. R-Rainbow!" Twilight yelled, grabbing the book in her magic and flipping to page 647. She knew exactly what page it was on because this particular spell had intrigued her the most during her little reading session earlier.
"Transformation magic?" What are you implying Twi?" Rainbow asked acting as curious as possible. She knew Twilight would flip to this page. She had made sure of this since she borrowed the book from Rarity a couple days ago. She asked Rarity to fade all the writing in the 920 page book except for page 647, that way it would pop out more when Twilight started reading it, which Rainbow knew she would. It was just one of the many things Rainbow had come to discover of Twilight. When there was a book in front of Twilight, she will read it.
With a smile Rainbow put the final act of her plan into action. "Twilight.. C-Could you do something for me?"
Looking up from reading the spells details. Twilight gave a curious look at Rainbow as a queue to keep talking. "W-well.. I was wondering if.. M-maybe you could.. Couldyoutransformmeintoadidldoanduseme?" Rainbow shot out. She was fidgeting in her spot and it wasn't because she was horny out of her mind, at least that was only part of the reason.
Twilights curious gaze turned to one of surprise. Even though Rainbow had shot that out at sonic rainboom speeds, she understood what she meant. Dash wanted to be turned into a toy so she could use her.. It was.. Erotic. That was the only word Twilight could really think of and to say she wasn't a tad bit curious at how that was going to work, she would be lying. "O-ok. I'll do it." Twilight spoke, nodding her head in agreement.
Rainbow was taken aback. Even though her plan had been completed, she didn't really know what to expect when she actually got to this point. But yes? She said yes. "R-Really? If you don't want to that's fine I.." For some reason she couldn't finish that sentence.
Twilight sat up and turned to face Rainbow, the book now in her magic floating in front of her. "Dash I'm going to be honest. I wasn't expecting this, but I'm glad you brought this up." Grinning, Twilight lit up her horn and began performing the spell. "I'm also going to be honest with you in saying that I'm very intrigued by this suggestion. It says here that if used on a other pony, they feel pleasure just like as if it was being used on them too."
Twilight giggled as she watched Rainbow sitting in front of her, not really knowing what to do with herself. She knew what was coming, but she didn't really know what it was going to feel like or be like. This was all new to both of them. But with the tingly feeling back between her legs, she was definitely exited for whatever was about to happen.
With the spell nearly complete Twilight grinned as she recalled an earlier line. "Don't worry Dash.. I wont hurt you." In an instant Rainbows figure was gone. Twilight peered down and she grinned giddily as she saw none other than Rainbow, but only it wasn't. The cyan colour toy looked like any stallions cock out there. Fairly big too. Twilight giggled at that. The spell said if used on a mare it would accurately depict there size if they were a full grown stallion. Rainbow would have been a large stallion. Probably very muscular too, even more than she is now.
Biting her lip Twilight picked the dildo in her magic with care, she knew that this toy not even a minute ago was a fully grown mare, sitting right in front of her. Now soon she's going to be inside.. Shivering at the thought Twilight got up onto her bed and laid down on her back, spreading her legs she moved Rainbow between her legs and rubbed her against her lower lips.
The pleasure she was receiving from this was conflicting her. She knew what, or in this case who, she was rubbing against her vagina and.. It was interesting, but she loved it. It felt better than anything her and Dash have done, period. Putting the first inch of stallion meat inside of her Twilight moaned into her hoof as she bit down on it. It was almost too much pleasure to handle. She hoped Dash was feeling this just as much as her.
Pushing another couple inches into her now very slick cavern Twilight bit down hard onto her hoof as the waves of pleasure flew through her. She was only 5 inches, maybe 6 inches in, but she needed to go in more. She wanted, no needed Rainbow deeper inside of her. With one deep breath Twilight gripped Dash tight by the base and thrusted into her vagina at forces Rainbow would be proud of. The bedsheets were as wet as a splash pad as Twilight shot up, her back leaving the bed as her whole body convulsed, but not from an orgasm, from sheer pleasure. Slowly laying back down Twilight gripped the dildo she accidently let go of back in her magic and began slowly gliding Dash in and out of her vagina.
By now she was about to burst. The straight pleasure was so much to handle an orgasm was going to be a breeze to reach. Starting to pump the cyan dildo into her harder and faster than before, Twilight was determined to squirt all over Rainbow. She found that extremely hot and she didn't know if that was a good thing or not, but right now that didn't matter in the slightest. She was a bad girl that needed to be punished by her mare. Her mare that was deep inside of her. "MmmMMM! A-AH! R-RAINBOW I-I'M CUMMING!"
As Twilight started to squirt around the dildo, her eyes went wide as she herself felt something hot and sticky shoot inside of her. Twilight couldn't believe what she was feeling. Rainbow was squirting inside of her, deep inside of her. "MMMMmhhnnnn.." Twilight moaned along as he road the waves of pleasure she was feeling all at once. Having Rainbow squirt so deep inside her and watching it leak out around the base of the dildo was something you could only wish of, while you're on drugs. It was something of dreams, but here she was feeling it, seeing it happen right before her eyes and she loved every bit of it.
Feeling the leaking of juices come to a halt Twilight pulled Rainbow out of her and set her down on the floor to her right. Focusing as best she could in her current state, Twilight lit her horn. Casting the reverse spell was easier than casting the transformation spell. In an instant Rainbow appeared where the dildo once was. Well, Rainbow was always there. Twilight shook her head. That part was always going to be confusing to her, no matter how many times they use the spell in the future. "R-Rainbow.. Are you.. Alright?" Twilight asked looking down towards the laying Pegasus.
Doing her best to sit up, Dash fell down back to her laying position. Clearly walking was something that she could not do right now. "Mmmyeah.. I.. I'm more than alright Twi.. I-I may need some help though."
Picking up her mare friend in her magic Twilight levitated her over the bed and laid her down in the empty space next to her. Her magical capabilities were coming back to her slowly, but with how intense that was.. It was going to take a good nights rest. Looking over to her side she pulled Rainbow close and put the covers over them both so they were snug and warm. What they both disserved after that was some rest, and Twilight was not objecting to that idea.
"Twi.. I.. I love you." Rainbow groggily spoke before passing out right then and there in Twilight's grip, the only place she ever wanted to fall asleep from now on.
Twilight smiled with a blush. This sleeping mare in her arms was the best thing to ever happen to her and she was never letting her go. "I know Dashie.. I love you too.." Twilight smiled as she closed her eyes for a well deserved rest. "By the way.. I know you took my battery."
