A dark and abandoned, dusty basement. The only source of light is from the rubble covered stairway entrance. The only animals in this place was a lone mole as it walked by the stairs, but to only be spooked by the sudden source of light and fallen rocks at the top of the entrance.

"Can't believe It's still here!" said a voice. Soon footsteps could be heard walking down the steps, revealing it was Alicorn Twilight, wearing her Princess dress as she has been ruling Equestria for a few years now. Her heels were clacking on the old wooden steps and her body was soon being illuminated by the glow of her horn as a light purple aura engulfed the fallen rocks, saving the poor mole from a quick death. Once the rocks were levitated off the stairs, they were all set down with a small crash and the mole looked at the Princess who only smiled at the mole and nodded her head as the mole ran away, leaving the room.

Twilight looked around, amazed at the old things. "Once Starlight told me she found a part of the basement wing of Golden Oak Library, I was so shocked and happy to hear that! So much history and memories are here." Twilight then walked up to an old box filled with her old experiments she did in the past. She took out a helmet that she used on Pinkie back when she was trying to figure out how Pinkie's Pinkie sense worked. She sighed, filled with all the old emotions of how she was back then.

"More like old junk than history, Twi," Dash said, hovering down the steps.

Twilight turned to see the current Wonderbolt's Captain, Rainbow Dash, who was in her off duty uniform and wearing her bomber jacket. She was flying in, flapping her wings as she hovered a few feet off the ground before she landed with a smirk on her face.

"Hey, a lot of these are old inventions I remembered!" Dash picked up the metal square item, smiling at it. "Didn't you used this on me to see if my speed during Sonic Rainboom had some magical force?" she spun it on her finger like a basketball. "Man, remembering how awesome I was and still am makes me so nostalgic!" she gave a cocky smile.

Twilight look down at Dash, since Twilight had grown taller over the years. She gave Dash a deadpan stare. "Dash. That's a toaster."

Dash stopped spinning the metal square item, making it pop out moldy bread from its slots. Dash was shocked, looking at the moldy, rotted, stinky bread. "Toast!? You made me fly superfast just to make toast?!" Dash joked, tossing the item behind her shoulder.

Twilight only shook her head with a smile, looking around the place. "Shame the girls couldn't help me with moving some of these things out of here."

Twilight started to search through the boxes and other miscellaneous things as Dash was just leaning against the wall. "Yeah, well, you have me, right? The fastest Wonderbolt and Pegasus alive can clear this junk in ten seconds flat!" she bragged.

Twilight gave a chuckle. "Sure, but it wouldn't be fair if you just left me with all this junk up in the Castle of Friendship basement and went home. I also need help in organizing the things that are useful. We can't just toss everything out."

"Yeah, yeah, you got a point." Dash said, walking over to Twilight, who stood up and bumped her head on the dirt ceiling. Dash covered her mouth as she was trying not to laugh.

Twilight blushed. "Don't."

Dash was struggling not to laugh. "How's the weather up there, your tall highness?"

Twilight rolled her eyes. "It's not funny."

"Oh, it's very funny." Dash smirked. "You can't even walk here without bumping your head! Just like when you visit our houses!"

Twilight blushed harder as she remembered how she will always bump her head on the door frames and ceilings when she visits her friend's house...every time. What made it worst was hearing Rainbow Dash's laughter at her misfortune.

"Alright, alright, I'm sorry." Dash finally said, wiping a tear from her eye. "Anyway, should we start on this soda collection you have here on this wall shelf?"

"No, the first thing we need to do is get rid of the spider webs and dust!" Twilight, who was hitch over, said, pulling a book from a bookshelf, coughing from all the dust she raised. She was about to open the book when the realizing hit her. "Soda collection? What soda collection?" she asked.

Dash pointed her thumb to the wall shelf that was right next to the bookshelf. "The one right there."

Twilight's eyes widened, seeing the huge collection of bottles filled with various kinds of liquid, all neatly arranged and covered with dust. Twilight's eyes went with joy, as she couldn't believe her old potions she made all those years ago were still in one piece and in perfect condition.

"These aren't soda drinks, Rainbow! These are my experimental potions I used to make back when I was a unicorn!"

"Potions?" Dash asked, looking at the colorful liquids. "So, you're saying you can drink them?"

"No! At least, I think." Twilight answered.

"You think?"

"I don't know. I mean, I don't remember what these potions did." Twilight said. She placed her hand under her chin, talking to herself. "Maybe we should test these?"

Dash held a bottle and looked at it. She couldn't help but smile. "Like the good old days when you ask me to help you with your weird experiments and being tied down in those weird knots. Man, I missed those." Dash said, looking at the bottle.

"Rainbow, be careful with that! You don't know what could happen if you drink that!" Twilight blushed. "And those experiments weren't weird! It was important for future reference for the greater good of Equestria!"

Dash rolled her eyes. "Sure, whatever you say, Twi." she then looked up at her while tossing the bottle up and down like a softball. "But really, those knots you did on me. What kind of knot was that? It's not any I have ever seen before, and I was in the girls scouts!"

"Oh, it's not any normal knot." Twilight blushed harder. "I invented it. It was meant for...special cases."

Dash raised an eyebrow. "Special cases? You mean like the knots that can hold a strong Pegasus in one place?" she stopped tossing the bottle in the air and pointed it at Twilight with a smug look. "Like me?"

Twilight gulped. She felt like her heart was about to burst out her chest. She was caught red-handed, but she couldn't tell Rainbow what that knot was for! That knot was designed specifically for Dash! For her to be tied in that position, being helpless and being dominated by the one who tied her down, being forced to orgasm as many times as the person wanted. But Twilight couldn't admit that to Rainbow her kink fantasy, so instead she came up with a little white lie.

"N-No. T-Those knots are used for the ones that have a tendency to run off from their duties." she looked down at her, staring blankly. "Like someone I know when they refused to help and wanted to run off..."

Dash sweated as she pulled her uniform collar. "Right...uh, let's not talk about the past. We got a lot of work ahead of us!" she then placed the bottle down on the shelf, gently as to not break it, but she realized something and smirk. "So...you call that knot a..." she looked up, seeing an annoyed Twilight, as she knew where Dash was heading with this. "...running knot!"

Twilight sighed loudly. "Dash..."

"Get it? Cause you tie someone down with a running knot, and they can't run-"

"Rainbow Dash! That's enough! Please!"

"Fine, fine, but come on! That was pretty good, right?" Dash smiled.

Twilight sighed and rolled her eyes. "It was the corniest joke I have ever heard."

Dash shrugged and watched as Twilight moved her head closer to the shelf, looking at each potion. Dash smiled as she could see Twilight trying to hide her giggling face. "Another hit joke." Dash whispered.

The two were checking each potion for a bit, but Dash thought up of another joke and looked up at Twilight. A small smirk formed on her face.

"Back to what we were talking about. So the nevertheless, someone can drink these potions, right?"

Twilight was still near the shelf, eyeing each potion. "Well, sure, I guess. Why do you-"

"Then one can say that these drinks can be labeled as-"

Twilight stopped checking the potions and knew what Dash was going to say as she closed her eyes, unknowing a tiny spider lowered down near her face. "Don't! I swear Rainbow! If you say-!"

"SODA POP!"

"NOOO!"

Twilight opened her angry eyes but froze as she saw the tiny spider waving at her.

They both blinked.

"AH!" Twilight screamed, stumbling back and standing up, but only to smack the top of her head against the ceiling, sending dust and dirt flying everywhere, and the spider scurried off as the force of Twilight's head hitting the ceiling made some of the potions shake, and one potion tipped over and fell off the shelf.

Dash laughter stopped as the potion landed on her head, shattering the glass and pouring the liquid on her. Twilight lowered her head and cursing up a storm as she rubbed her head, but her anger faded away as her eyes widened, seeing what happened.

"Dash!?"

Dash was standing there, completely fine...well, minus her clothes melting away.

"Whoa, what the heck!?" Dash asked, shocked as her jacket and shirt melted away and fell on the floor, showing her upper torso, her muscular arms, and her abs. Her boots melted away too, and not even her underwear was safe.

"Uh, oh, this can't be good." Twilight said, worried.

"What did you put in that thing!? A clothes' dissolver?!" Dash asked, looking down at herself, feeling her bare flat chest, and other parts of her upper body. "At least my hair is still there." She felt her abs and sighed with relief. "And my sexy six-pack."

Twilight closed her eyes, as Dash was now completely naked and her clothes were nothing but melted puddles. "I'm so sorry, Dash!"

Dash was about to say it's okay and felt like the good old days in how Twilight's experiments almost always started, but quickly noticed Twilight was struggling to move around the basement, as she couldn't see with her eyes closed. "Twi!" she noticed that Twilight was coming back and about to hit the bookshelf near the wall of potions, and when she did, a comedic large potion somehow fitting on the small shelf tipped over and rolled off. "Crap..."

"What?" Twilight asked, hearing a large sound of a glass bottle shattering. She opened her eyes and could see Dash covered in pink liquid. Whatever the potion was, it quickly absorbs into Dash's skin. "Dash!? Are you-"

"I feel...strange..." Dash said, her body heating up.

"Strange how?" Twilight asked, her cheeks turning red as she could see Dash's whole naked body, including her lower areas.

Dash's eyes were closed as she was blushing hard. "Uh...well..."

"Is it painful?" Twilight asked.

"Not really. More like..." Dash's cheeks grew hotter, and she had to hold her lower regions, since her lower parts were starting to glow and something long, thick and huge burst out with balls. Twilight was in shock as she knew what had happened. She gulped as Dash's cock came into full view and it was massive! "...really really sensitive."

Twilight was shocked, staring at the massive horse cock in front of her. It was easily more than a foot long and had a wide girth to it. The balls were also large and hanging low. The cock had veins going up the length, and a thick mushroom-shaped head, and the base was surrounded by Dash's rainbow pubic hairs. Twilight gulped again as she remembered, back in the day, she was testing a potion that will make the user grow a cock. It was a failure, and she shelved it with the other potions.

"Why did it work all of a sudden? Did the ingredients in the potion needed to age?" Twilight mumbled, staring at the huge cock and balls. "Maybe the temperature was the key? Or did the mixing of the first potion caused this?"

"Um, Twilight." Dash said. "Why did you made a dick growth potion?" pointing at her large penis.

Twilight gasped and covered her mouth, embarrassed. "O-Oh! W-Well, it was a failed experiment. I never expected it would actually work!"

Dash was shocked but yet, not surprised. "Of course the singleAlicorn Princess would make something like this. You're the one who has the craziest experiments, after all. But, um, can you fix this?" she asked, trying to move but feeling the monster of a dong slapping against her leg and the balls swinging. "This is getting weird."

Twilight looked around. She couldn't find anything. She was sure there were more potion ingredients back here. She didn't know why this was happening, but she didn't want to give Dash hope in fixing this right away. "I'm not sure. I would have to search through all the boxes and junk and hope to find the right ingredient to reverse the process, but it would take hours, maybe even longer like weeks or months." She started to have a mini-freak out. "And I have no idea if the ingredient would be still fresh, or expired, and we don't even know if you can turn back to normal. What if it's permanent, and you are stuck like that forever?! And what would everypony else think!? Oh, Celestia, how will I ever explain this to your family and the girls!?" she has begun to walk back and forth, rubbing her hands through her head. "What will the papers think, and the people of Equestria when this comes out?! I can see the headline now, 'Princess Twilight Sparkle has a new weapon she has invented that makes mares grow dicks!' And not to mention-!"

Twilight stopped as she heard laughter coming from Dash below.

"Rainbow? Why are you laughing? This is serious!"

"Pfft, it's just a cock, Twi. And seeing you act like your old self brings back so many memories." She gave a smile. "And, yeah, this is pretty bad, but I don't think you should worry about it. Just think of this as an experiment gone wrong, and we can try and fix it. You know, like yesteryear"

"Dash...why are you not freaking out about this? Like, you're acting like this is no big deal." Twilight pointed out, calming down, but a bit. She started to hear what Dash was saying to her but to some odd reason, Twilight's eyes slowly looked down, and she was staring at Dash's cock and balls. Her cheeks were turning redder, and her legs were squeezing together. 'Why is she not freaking out about having a huge cock and balls? Is it because she's a tomboy?' She toned out Dash as she started to make another joke. Twilight could feel herself getting horny as she stared at the thick shaft. She didn't know what was coming over her, but the sight of it was making her hornier by the second. 'What is happening to me? Am I becoming aroused from seeing a female with a penis?'

"But if this thing is permanent, then I'm sure there are some perks that come with it." Dash continued, oblivious to Twilight staring at her dick. "Like I can brag I have the biggest balls now!"

Twilight licked her lips as she could see some pre-cum coming from the head. She could feel her body getting hot, and she could feel her pussy wetting her panties. 'Why is seeing this making me feel so...'

"And I bet I can score with the straightest mares easier than ever now."

"Yeah..."

Twilight lowered herself to Dash's level and, without thinking much of it, held the cock in her hands. She could feel the thick shaft throbbing and pulsing, and the warmth coming from it, and her eyes were filled with lust and desire. She wanted this cock in her pussy so badly.

Dash looked down, confused. "Um, Twilight? What are you-?"

"Shut up and let me suck your dick." Twilight said, and without warning, she shoved the head into her mouth.

Dash was shocked, her mind unable to process the situation. She couldn't believe what Twilight was doing! And she couldn't believe the feeling. Twilight's mouth was so warm, and the feeling of her tongue moving around and her lips sucking her head. She couldn't believe Twilight was giving her a blowjob.

Twilight bobbed her head up and down, taking the whole head and half of the shaft, swirling her tongue around the mushroom shaped head, tasting the pre-cum leaking out. She could hear Dash moaning and her own heart beating faster. She never had sex before. Sure, she had done plenty of things in her free time to learn sexual stuff, and even practiced on a fake penis, but doing the real thing was completely different. But she was enjoying the taste and the sounds Dash was making. She could feel her own panties being soaked from her juices.

Twilight pulled her mouth off with a pop. She was breathing hard, her body was burning, and she couldn't believe her own actions. She was blowing one of her friends like a slut...and she was loving it! She couldn't stop herself as she was jerking the whole length, using her other hand to rub the large balls, feeling the heavy orbs.

"What are you doing?" Dash asked, moaning from Twilight's touch. She was in heaven. It felt amazing, and she could feel her orgasm coming as she felt Twilight's mouth once more, but she held it back. She couldn't dare shot her load inside Twilight's mouth, especially while Twilight is the Princess.

Twilight couldn't stop her actions, and she felt a small bit of shame as she answered. "I-I don't know." She looked up at Dash, her eyes full of lust and want. "I'm just letting my body guide me, and I don't know why, but I'm really enjoying myself."

Dash wasn't listening as she tried her hardest to hold in her load. She couldn't believe what was happening. Her best friend was sucking her cock. Not only that, but she was getting turned on by this, and it was clear from her own body.

"Mmm, Rainbow. You're so thick." Twilight moaned, licking the shaft. She moved her tongue to the base, rubbing her face against it and the balls, smelling the musky odor that it had. She could feel the balls twitching and the shaft pulsing.

"T-Twilight, I'm about to cum!" Dash moaned, holding Twilight's head with her hand, pushing her closer to her cock.

"Do it." Twilight said, moving her head back. "Cum all over me."

Twilight could feel the head touching her lips, and she opened her mouth and sticking out her tongue. She then closed her eyes, ready for the huge load. Dash opened one eye, seeing Twilight, a huge slutty smile on her face, her tongue waiting for the huge cumshot. That was enough for Dash to lose control...well, not really.

"I can't!"

Dash moved her cock away from Twilight's face, blasting her cum on the dirt floor. Twilight opened her eyes and saw the sad sight of pretty good cum being wasted, and the disappointed face of a blue Pegasus.

"Aww, why did you do that, Rainbow?" Twilight asked, her tone showing she was annoyed and angry.

Dash breathed a bit, calming herself. "Look, I know you're the Princess, but I can't just shoot my load on your face! Now, if word gets out I came over the fucking Princess of Friendship's face, then that would be bad for both of us." she couldn't help but make a small joke as she looked away in embarrassment. "Or should I call you the Princess of friends with benefits now."

Dash waited for the snarky and annoyed reply from the Twilight, but instead, she was met with silence. Dash looked at her, and the expression on her face was a complete surprise. Twilight was on all fours, licking up the cum that was splattered on the floor. Dash couldn't believe it! She was cleaning up the cum off the floor, like a dog! Sighting someone all mighty and ruler of the land...acting like a dog was such a turn on for Dash as her cock started to harden again.

"What are you doing?" Dash asked, looking down.

Twilight's response was her crawling over to Dash, sitting back up, and kissing her cock. Dash couldn't believe it! Her best friend was making out with her cock and almost like she was worshiping it!

"I couldn't let all that delicious cum go to waste, Rainbow." Twilight said, stroking the cock. "You have no idea how many times I dreamt of having cum on my face!" she kissed the tip, feeling the cum covering her lips and tongue. "Mmm, and I love the taste. So sweet and musky." She smiled, staring up at Dash. "I think this will be the beginning of a great relationship."

Dash blushed hard. She had to admit, this was a dream come true. Here, her best friend and crush was sucking her cock and enjoying it! She will be fucking Twilight soon enough, and who knows what else might happen in the future?

"Uh, yeah, but are you okay, Twilight?" Dash asked, unsure about what is going on.

Twilight ignored her, focusing on the massive cock. "I'm sorry, Rainbow, but can we talk later? I'm in the middle of worshiping this monster."

Dash couldn't take her eyes off her best friend as Twilight's face was being shoved into her massive nuts. Dash could feel Twilight's tongue moving along the balls, and her eyes filled with lust and hunger. 'She's a slut!' Dash thought. "Twilight, I'm not sure what's going on, but you need to stop!" she tried to pull her cock away, but she was shock to see how desperate and horny Twilight was. "Stop!"

Dash pushed her away, and Twilight's body fell onto the dirt floor, covering her white dress with dirt. She moaned, the taste of the cum and musky odor still in her mouth, and she could feel her panties were completely soaked, and her pussy was craving a cock.

"Rainbow, what are you doing?!" she shouted, angrily. She crawled back to her, trying to touch the monster of all cocks, but Dash kept her at bay with her bare feet. Twilight lowered herself to the ground, her voice sounded so desperate as she begged, "Please, let me suck your cock again. I'm begging you!"

"No! This is wrong! We shouldn't be doing this!" Dash shouted, not believing the situation.

"Rainbow, I'm really horny and need a good fucking. I'm begging you." Twilight begged, licking the toes. "I'll do anything! Please!"

"What is happening to you?!"

Twilight could feel her mind slowly being lost. She couldn't take it anymore! She needed this cock in her pussy right now!

"Dash, please, we'll figure that out later, but kindly let me have a go with your dick. Please."

Dash was stunned, not sure what to do. This was completely new to her. Twilight was begging for her cock, and it was turning her on, but she couldn't fuck her like this. She couldn't help but make a joke of the situation, hoping to snap Twilight out of it, but also for Dash to keep herself from jumping on her poor friend.

"Um, well, if you're begging for it, then that means you'll tell me what fetishes you are into."

Twilight didn't hesitate. "Bondage and pet play!"

Dash blinked with wide eyes, her cock throbbing. She was surprised that her best friend has those kinks. Maybe they're similar than she thought. She kept listening as Twilight went on.

"Remember the knots you were talking about!? Those were bondage knots! I wanted to tie you and be my helpless test subjects as I fantasy that while we were doing my experiments!"

Dash blinked, and she thought all about the experiments they did, remembering the weird knots on her body and why Twilight forced her to wear a blindfold and a gag ball. "That makes... so much sense." she said annoyed, anger and embarrassment rising.

Dash looked down at her, seeing Twilight still on all fours, kissing her bare feet while wagging her tail. She was a slutty mess. A very beautiful and sexy slutty mess. Dash looked at a box filled with rope and the very things that Twilight used on her.

"Okay Twilight. If you want my dick so much, we should turn this into an experimental test like good old days." Dash walked to it and took out the rope, gag ball and the blindfold. "But this time, I'm the one who leading this experiment, and you are the test subject."

Dash could see the look on Twilight's face, and she could feel herself growing harder. Twilight's eyes were wide, and her cheeks were blushing. It was clear, Twilight was turned on from what she heard, and Dash knew Twilight was getting wetter by the second.

"Oh, yes, Rainbow! I would love to be your test subject! Please, use me! Turn me into your slutty slave and fuck my brains out! Please!"

"You're getting a little too excited and ahead of yourself." Dash said, walking back. She lowered herself to Twilight's face, holding the gag ball near her. "Open."

Twilight did as she was told and opened her mouth. She could feel the ball entering her mouth, and she could taste the flavor of the ball. She then felt the straps around her head, and she was now gagged.

"Good, now I'll tie you up the same way you did with me all those freaking times!"

Dash did the same rope bondage technique and placed Twilight's wrists behind her back, then tied her wrists together. Dash will later learn of the name of the technique which was called "Strappado", her ankles were next as they were tied together and then tied to the rope on the wrist. Dash, without knowing, did the Shibari gyaku ebi tie technique. Dash removed the heels and tossed them away.

"Okay, now that you're all tied up, I'll put this blindfold on you, and we can start doing 'testing'."

Twilight could feel her pantyhose covered feet being touched by Dash's balls as the Pegasus flew over her and landed on top of her. Soon, Twilight saw only darkness as the blindfold was on.

"Mm, mmm!" Twilight moaned. She couldn't believe it! She was being turned on from this. The rope was tight and digging into her skin, her legs were tied, and her mouth was filled with a ball gag, and she could feel Dash's monster cock rubbing against the back of her head and neck. To her, it was like Dash pouring lotion on her as the pre-cum were sliding down her back. "Mm, mm!"

"Okay, here we go, Twilight. Time to test out why you are such a damn slut!" Dash said, her cock was pressing against the back of the Princess' head.

"Mm-hm!" Twilight nodded, eagerly. Hearing Dash walking over to her front now.

Dash lowered herself, and she held the base of her cock, her balls hanging low and resting on Twilight's hair. She then smacked the thick shaft on Twilight's head, causing her to moan loudly.

"Damn, I'm a lot bigger than I thought." Dash commented.

"MMM!" Twilight moaned, loving the feeling of the massive cock hitting the top of her head.

"You're probably enjoying this, aren't you?"

"MM-HMM!"

"Okay, time for the next part." Dash lifted her balls and moving backwards into a new position.

"Mm?"

Twilight was shocked when she felt something wet and thick smacking across her face. 'Cock! Cock!' she thought, happily. She was in heaven! Dash's monster cock was smacking her in the face. She could smell the odor and pre-cum covering her face, and the feeling of the veins and thickness was incredible.

Dash could hear her moaning and the sound of the pre-cum was landing on her face. Dash knew this was wrong, but she couldn't help herself. This was turning her on, and seeing Twilight, the Princess, was acting like a slut and wanting her dick made Dash's cock throb with want and need.

'I'm going to fuck the living shit out of you, Twilight.' Dash thought. She was planning to give Twilight the best fuck she could ever experience, and maybe, just maybe, make Twilight her sex slave...also her marefriend as a bonus.

"MMMM!"

Twilight felt the cock smacking against her face again. The warm rod was covering her face, and she could feel the thick and long length of the cock as it hit her cheeks and forehead, and even her nose.

"MM-Mmm!" Twilight moaned. 'Dash's dick is huge!' She could feel the warmth coming from the cock, and she could smell the aroma of Dash's balls.
Dash stopped smacking Twilight's face, and placed her penis under Twilight's nose, pushing the nose up. Twilight's nose looked like a pig nose, as she was smelling the odor.

"How does my cock smell, slut?"

"Mm-Hm." Twilight moaned, happily. "MMM!"

"Heh, thought so."

Dash moved her cock back and started to stroke her cock, looking at Twilight, her eyes covered, and her body was helpless and bound. Her nipples visible and erect through the white dress. She was a mess, and the fact Twilight was enjoying being humiliated was making Dash stroke her dick harder.

'Fuck, her breasts look so damn nice. They're so big, and I want to feel them so bad!' Dash thought, pumping her hand faster.

Dash was getting close. She didn't know how long she was stroking her cock, but the sight of Twilight, her best friend and the Princess of Friendship, bound and helpless was turning her on and was making her want to shoot her load all over her.

"FUCK!"

Dash came hard, her cock pulsing and her balls twitching. She could see the cum flying through the air and landing all over Twilight. The Princess that many looked up and will die for, was covered in thick sticky cum, her whole upper body was covered, and Dash had a huge smile on her face as her tongue hung out, breathing heavily.

"Fuck..."

Twilight was breathing hard. She could feel the warm shower of cum landing on her face and most of the back. She loved the smell, the feeling, the warmth, everything. She was so turned on, and her pussy was getting wetter by the second, and her body was aching and throbbing for the Pegasus' monster cock. She tried to speak, but the gag ball was stopping her from saying anything.

Dash looked down at her, her cock was softening, and she was breathing heavily. She was in awe. The sight of seeing the Princess was covered in her cum was amazing, and the fact that Twilight was enjoying this made Dash want more.

'Fuck, I can't believe she likes this! And...I kind of liked it myself.'

Twilight tried to move her tied up body, as she wanted to be near that blue cock. She wanted it in her so badly.

"Hey, no moving, slut!"

Dash stood up, her soft cock flapping a bit, and she flew over Twilight and landed on top of her. Twilight was wondering what Dash was planning to do next. She suddenly then felt something thick and hot between her feet. 'Cock!'

Dash was using Twilight's feet as a makeshift foot job, her soft cock slowly hardening again.

"Heh, I bet you love the fact I'm using your feet as a fleshlight. Don't ya, slut?" Dash asked, teasingly.

Twilight couldn't take it anymore. She couldn't handle being teased and turned on, and the fact she couldn't touch the monster cock. It was killing her inside. She was so beyond turned on that her wings spread out, signaling to Dash that she wanted to mate with her, like how birds would do it.
Dash felt up Twilight's pantyhose legs while still thrusting her hardening cock between the Princess' feet.

"Damn, never thought I'll be feet fucking a Princess feet like this! Man, if Celestia was here now or any of the Royal leaders, they would be pissed off that the Princess was acting like a slut." Dash laughed.

"MMM!" Twilight moaned, wanting more. She was hoping for Dash to fuck her pussy already, but the teasing and bondage was too much. She could feel herself cumming, and she tried to hold it back.

"But I guess there is some perks having a best friend as a Princess. Like using her body for my pleasure and-"

"MMM!" Twilight moaned, trying to get her attention.

"Huh?"

Dash stopped talking and looked down. Her eyes widened as she saw that Twilight was shaking, her hips were moving, and the scent of her juices were leaking out. Dash smirk.

"Then let's cum together, Twi! I'll make sure that this is the best orgasm you will ever have!"

Dash started to hump the feet harder, her cock growing harder by the second. Twilight's toes and palm of the feet were rubbing the mushroom shaped head and the underside of the shaft. The feeling was amazing.

"MMMM!" Twilight moaned loudly, her body twitching and her wings spreading out further.

"Fuck, I'm about to cum!" Dash shouted, thrusting her hips.

"MMMM!"

"Here I go!"

"MMM!!!"

Dash shot her load between the feet, covering the feet and the toes in her sticky and thick seed. She could feel her cock being milked by the feet, and Twilight's legs were twitching, and she could hear her moaning. Dash had a smile on her face, knowing that she and Twilight had a mutual orgasm.

"Ah, fuck."

Twilight's legs were relaxed but still being hung in the air thanks to the rope, and her body was breathing hard. She could hear Rainbow walking away and sounds of things being opened and closed. She wondered what Dash was doing.

'Where did she go? Did she leave me like this?'

Soon, she felt the gag ball being removed and then followed by the blindfold and she was greeted with a collar in front of her. Twilight eyes looked up, seeing Dash smiling.

"I'll fuck you but if you be my little cute pet, Twi. I'll make sure to fuck the shit out of you."

Twilight couldn't believe what she heard. Dash was asking her to be her pet! That was something Twilight didn't expect, but her body was screaming and begging her to agree.

"Y-Yes!"

Dash smiled and placed the collar on her, then removing the rest of the rope. Dash looked down at the horny Princess and, looking so weak.

"I won't lie, Twi. I always wanted to do this, and I'm sure others did too."

Dash lowered herself and forcibly ripped off Twilight's dress like she was going to rape her.

"R-Rainbow?"

"Shh." Dash placed her fingers over Twilight's lips. "You wanted this, didn't you?" Dash asked, her finger moving along the lips. "To have my cock, right?"

"Yes! I wanted your cock for a long time!" Twilight moaned, as she felt her bra being forced off, freeing her large breast to Dash. "I want this!" Soon, her panties were ripped off, exposing her wet pussy to the Pegasus.

Dash was looking at Twilight, seeing the most beautiful and sexy sight she ever saw. The Princess, Twilight, was naked, and looking like a sex slave. Dash pulled the chain that was on the collar, and forced her to the stairs.

"Let's go for a walk, my little slut of a pet." Dash said, leading her like a dog.

Twilight didn't care about the way she was being treated. She was loving it. Loving the rough treatment and the feeling of being dominated.

"Yes, please."

Dash led Twilight up the stairs and into the basement of the Castle of Friendship. After that, she leaded her to the main floor and looking for someone, and that someone was...

"Now, where is Starlight? I want to show her my new dog."

Starlight was walking down the castle's hallway, carrying some books that needed to be returned to the library. She walked into the library. She was going to walk over to the shelves when she heard something, which sounded like someone was dragging something across the floor.

"Hello?"

Starlight walked towards the source of the noise. Whatever it was, it was a few rows down. She stopped and slowly peeked out, and what she saw was....

"A dog?" Starlight said, walking out and seeing a large purple dog sitting there, wagging its fluffy tail. She could see the dog had a collar and a leash, but no owner. She sighed and kneel down. "Looks like someone got inside my home? Come here! Let me look at you."

"Bark."

The dog quickly ran and leapt on Starlight, pushing her down, and started to lick her face. Starlight was surprised and shocked at first, but the feeling of the tongue on her face was tickling her, and she started to laugh.

"Hehe, haha! Stop it!" she giggled, trying to push the dog off.

The dog soon stopped, and Starlight wiped the saliva off her face. She looked between the legs of the dog and noticing it was female for two reasons. It had a vagina, but also it was dripping wet.

"Oh, you are a girl and seemed to be in heat. Where's your owner?"

"Bark!"

Suddenly, the dog started to lick her neck and her cheek, and Starlight giggle again.

"Haha! Stop, hehe, I get it. You're in heat and-hmm?"

She could feel the dog tongue entering her mouth a few times.

"Hmm?"

The dog then started to rub its vagina on Starlight's leg. The wetness was staining the leggings, and Starlight was starting to worry.

"Hey, stop. Bad dog. That's not a good idea. I'm not a-"

The dog started to rub its vagina against the crotch of Starlight's leggings harder.

Unknowing to Starlight, this wasn't a normal dog but naked Twilight herself, using illusion to trick Starlight's mind with replacing her body with the body of a dog. Twilight wasn't licking, but kissing Starlight's neck and then on the lips, while rubbing her crotch all over Starlight's leg like a horny mutt she was.

"Okay, stop. You're really bad. I'm not a male. Now, I'll be nice and let you stay here until I find your owner, but you need to stop. If anyone sees this, they'll-"

Poor Starlight couldn't finish as Twilight kissed her on the lips very passionately. The tongue was swirling around the inside of her mouth, and the taste of Twilight's saliva were in her mouth.

As this was happening, Dash was watching this right in front of them, all thanks to Twilight's magic that she forced her to use.

"Man Twilight, you're truly more powerful than Starlight, huh? I thought for sure she would see through it, but nope! She can't see that it's you, and the fact she thinks you're a dog is even better!" Dash said, laughing quietly. "Well, enough teasing and get off of her and be a good dog."

Dash picked up the leash and pulled on her, signaling her pet to listen and follow what she had ordered her to do. Twilight was on her knees, and the kiss was broken, and the saliva trail was seen between their mouths.

"Bark!"

Twilight got off of Starlight and lay on her back, exposing her stomach to her. Starlight smiled as she sat up and placed her hands over the fluffy dog.

"Good girl, now don't be naughty! Who's a good girl, huh? You are!"

Twilight's tail wagged and she barked happily.

"Yeah, you're such a good girl."

Twilight felt so horny being treated like a dog and all people, it was by Starlight. She never knew she could do something like this.

"Bark! Bark!"

Twilight was getting closer and closer, her tongue hanging out, and her tail was wagging like crazy. She wanted to play with her pussy so bad...and like some higher power listened, she felt two fingers entering her vagina. This made her dog form ears perk up and even Dash was taken aback in what she saw happen.

"Who's a horny girl? You need some relief, huh? Don't worry, I'll make sure to give you plenty."

Starlight was fingering Twilight's pussy, her juices were covering her fingers. Her thumb was rubbing her clit, making the dog form Twilight moan in pleasure.

"Bark!?"

"Oh, you want me to do this faster? Is that it?"

"Bark!"

"Then I'll make you squirt all over the place!"

Starlight did just that, pumping her fingers in and out of Twilight's pussy, rubbing her clit, and her other hand was playing with her own breast. Twilight's tongue was hanging, and she was panting like a real dog, and she was close to cumming.
"BARK!"

"Yes, cum for me. Cum all over the floor."

"Bark! BARK!!!"

Twilight came, squirting her juices on the floor. Her wings spread, and her whole body twitched as she orgasmed. Starlight slowed her fingers down and then removed them. She licked her fingers clean and looked down at dog Twilight, seeing her lying on her side and her tongue hanging. Starlight looked around, making sure no one saw this.

Dash blinked and was still stunned of what she saw. "Okay, note to self. Tell the girls to not leave Starlight with their pets." she snapped out of her trance and looked down. "Okay, Twilight. I think you've had your fun and should be reward, but first." she lowered herself to her ear, whispering something.

Twilight's eyes went wide and her tail wagging quickly. She got up and ran to a nearby desk and raised her leg up. Starlight saw this and knew what was going to happen.

"Hey! No! Bad dog!"

She grabbed her just as the pee was coming out.

"Bad dog!"

Dash was holding back her laughter, seeing Starlight having her hands full and being covered in piss. She watched the sight as the yellow fluid was covering the floor and the desk, and the sight of it was amazing.

Starlight was breathing heavily, her clothes were drenched and smelled. She signed in annoyance and looked down at the dog that was now on her side, and her head was down.

"Bark..."

"No, don't bark! Bad dog! Don't pee on the desk or anywhere! That's not a good thing, and I need to clean this up." Starlight signed. She smelled her pee stain shirt, cringing from the smell. "But first, I need a bath and new clothes!"

Dash watched as Starlight tied the leash around the desk's leg and then left to get cleaned up and change. Dash was smiling, seeing how well this was going. She looked down at Twilight and pulled her by the leash, getting her on her knees again.

"That's my girl! And good girls need a reward."

Dash forced Twilight on her back and got between her legs. She looked down at her pussy, and her cock was fully erect and throbbing. She moved her mushroom tip to her entrance and slowly inserted her monster cock.

"Bark!"

Dash could feel the walls of Twilight's vagina, hugging her cock. She loved the feeling of it, and it was like she was being swallowed whole.

"Fuck, your pussy is so damn tight. Are you a virgin, Twilight? Did no one fucked you before?"

Twilight looked at her with puppy eyes, and Dash was loving this.

"Well, guess that makes me the first to fuck you and my first in fucking a Princess."

She started to thrust her cock, the warm and wet walls were massaging her dick. She could feel Twilight's juices covering her length, and the sounds of their groins slapping were echoing through the library.

"BARK!!!"

Dash was fucking her faster and harder, loving the sound of her cock sloshing in the juices and hearing how Twilight was still acting like a bitch that she was.

"Good girl! Be my pet, Twi! Be my sex slave, and I'll promise to make your body ache and wanting me! I'll be sure to make sure you are the best little sex toy in all of Equestria."

"Bark! Bark!"

Twilight was drooling, and her tongue was hanging. She was a mess and her body was a sweaty and sticky mess. Her juices were leaking all over Dash's cock and balls, and the Pegasus could feel herself close to cumming.

"Fuck, I'm gonna cum! You want it? You want my cum in your tight little doggy cunt? Ask for it, you bitch in heat!"

"BARK! BARK! BARK! BARK!"

"YESSSSSS!!!"

Dash came, filling Twilight's pussy up. Her cock was pushing against her cervix and her seed was spilling inside of her. Twilight was panting like a dog once more, and her tongue was hanging.

Dash took deep breaths and pulled out, her cock still hard. She could see her cum leaking out and she smirked.

"Damn, look at that. I guess that makes me the new Queen...or King?" she laughed. She could see Twilight was trying to get up, but she placed her hand on her chest and the other hand freeing the leash from the desk, keeping her down.

Twilight looked up, seeing Dash looming over her with a perverted smile. She felt the collar being pulled on and could feel her body being pushed up, her breasts and face against the cold floor.

"You're not finished yet, Twilight. I'm going to fuck you until you're too stupid to be the Princess, and all you will be is my little bitch. Do you understand?"

Twilight nodded and moaned. "Yes."

"Good, now I'll be fucking that ass next, and I'll be making sure you won't be walking straight for a week!"

"Bark! Bark, bark!

"Heh, I love how you act like a dog." she pulled the leash once more, showing Twilight she was the master now and also something else as she slammed her cock into Twilight's asshole, fucking it with quick thrusts. "And don't worry Twi, I won't make you too stupid in ruling because..."

Few weeks later

Sounds of heels were heard as someone was walking, and this someone was a familiar white Alicorn. It was former Princess Celestia, wearing a golden dress and matching heels. Rows of guards and maids lowered their heads as Celestia entered the hallway. She happily waved at them all and told them to stop, as she wasn't the Princess anymore.

She walked up to the large doorways of the throne room and the guards opened them. She stepped inside, seeing other Royal leaders and her own sister, Luna. She arrived late to the meeting with Twilight, who was sitting on the throne, listening to everyone, not saying much. Celestia felt so proud that she was correct in choosing Twilight to be the new ruler. She was the perfect Princess, and her words were being respected and listened too when she did spoke.

"My dearest former student..." Celestia wiped a single tear. "Twilight...I'm so proud of you."

Sounds of slurping could be heard in the throne room, but no one was reacting to it, as the whole castle was covering a purple aura.Sitting on the throne wasn't Twilight, as the real person sitting on the throne was Rainbow Dash, naked and wearing Twilight's crown as she pulled harder on the leash.

"Bark!"

On her knees and happily licking and sucking on Dash's cock, was Twilight. Reduced to nothing but a horny bitch in heat.

"Good girl, keep acting like that as the good girl you are."

Twilight kept licking and sucking the cock. Her collar jiggling as her head bobbed.

Dash had a smile on her face as she petted the former Princess.

"Who's my sweet princess?"

End

Author's Note

I want to say thanks to superfun for allowing me to write this story for them! Super fun and helpful to write as this is my first time writing bondage related fic!