2070671

by Reallyrealusername

Rating: mature
Tags: Equestria Girls, Sex, Twilight Sparkle, Porn
Length: 3725

Twilight agreed to help Sunset with an experiment. She didn't realize just what was in store for her.

Twilight comes to the human world for a day to help Sunset with an experiment she seemed eager to conduct during their conversations through the journal. Little did Twilight know what was about to happen to her.

Contains: Slight bondage, erotic electro-stim, and minor sounding.

Story inspired by Derpibooru image #2070671. Thanks to Pshyzo for the great art.

Disclaimer: All characters are 18

Published 2019-06-24 13:10:01 UTC
Last updated 2019-06-24 13:10:01 UTC

Willpower

Twilight stepped through the portal, quickly adjusting to her new form. Each time she passed through the portal it got easier, but no matter how many times she did it, it would always feel strange walking around on two legs. Spike always seemed to get accustomed to his four legged form faster than Twilight did to her human body. She theorized that it was because many dragons naturally walked on all fours anyway once they had fully grown.

No, no. That can wait, Twilight thought to herself, Today, I'm helping Sunset with her experiments.

Once she had fully gotten her bearing, she headed into the school. It was completely empty, but that was to be expected given that it was a Saturday. Most students would get kicked out or worse, if they were caught trespassing on school ground on the weekend, but after saving the school three times, Twilight and her friends had earned a certain standing with the administration.

It was through that positive standing, plus the fact that she's president of the yearbook committee, that Sunset was able to get permission to use the yearbook club's room. She did admit to Twilight that she wasn't entirely honest when asked what she was using the room for, but got Principal Celestia's okay nonetheless.

Following the directions from the map in the foyer, Twilight and Spike were quickly approaching the room number that Sunset had given her earlier. Just as Twilight turned the corner, she suddenly felt something smack into her, nearly sending her falling to the ground.

"Ow! Who's there? Oh, Twilight? You're early." Sunset was leaning against the wall, massaging her nose

"Oh, Sunset! I'm sorry, I finished my to-do list with a few minutes to spare, so I just thought it would be good if I got here a little-" Twilight was silenced by an orange hand pressed against her lips.

"Twilight, it's okay. You don't have to explain everything, I just didn't expect you to get here so soon." She pulled back her hand, letting Twilight speak once more.

"You're not mad at me for bumping in to you. Your nose looks like it hurts."

"No Twilight, I'm not mad. Accidents happen." She was, in truth, a little annoyed. Mostly by the tiny trickle of red running down her lip, but it was nothing she couldn't forget about once they got on with the test. "Now, if you're ready, we can get to work on the test.

Twilight nodded and followed Sunset as she turned and headed into the room that Twilight had been walking towards in the first place, Spike trailing behind at a generous distance, having learned long ago just how messy Twilight's experiments could get. The only other time Twilight had seen the yearbook club's room was during her first trip to CHS.

There was a bulletin board on the wall. It had a few picture of CHS students tacked to it, club membership info, budgeting for the club, and a few other general school reminders Twilight had already seen posted around the school. The two high budget printers were in the same spot as before, and looked just as impressive as they had the first time she had seen them. The only different is that she now actually knew what they did.

All of the computers in the back had been turned off except for one. Twilight could only assume that it was the one Sunset would be using to document the results of their experiments.

There was, however, one noticeable difference in the room. The center table had been taken out of the room and placed in the hallway. Instead, in its place, there was a strange looking set of contraptions. There was a small, black, object in the middle of the room that looked to be about the same size as one of those ZBox, or whatever it's called, things that Applejack and Rainbow had showed her during their sleepover. It had two rods sticking out from the top. One was light blue and had ridges going down most of its length. It looked to be around 8 inches long, and maybe an inch thick, with a round tip. The second was much thinner, but only a little shorter. It appeared to be made of metal and had a rounded tip as well. It didn't take long for her to deduce what the blue rod was for.

Coming out of either side of the device were leather straps, connected to what looked like a harness. There were also two padded cuffs mounted to the floor on either side of the device with the straps. The device was clearly meant to restrain someone, but to what end?

"Okay Twilight. First, I need you to take off your clothes." Sunset sat in the chair in front of the one computer not turned off, confirming Twilight's theory.

"Wait, isn't that against this world's social norms?" Twilight said, remembering a certain incident during her first trip to the new world.

"Normally, it is, but your clothes would interfere with the test, so it's okay to take them off now."

"Well, okay then." Twilight sat in one of the other chairs in the room, pulling off her bow tie. She could only imagine how annoying it would be to do an actual knot like this with hands, but thankfully, her's was only a clip on, so it was just a matter of pulling it off. She undid the buttons on her shirt and slid it down her arms.

She look around for a place to set her shirt and tie, eventually settling on the table beside the printers. Unfortunately, she had still yet to figure out how to remove her bra by herself and needed Sunset's help with it. From there, it was simple to take off her boots, socks, skirt, and underwear, all the while adding to the pile of clothing on the table.

"Alright, Sunset. What now?" Twilight asked, starting to feel a slight chill on her exposed flesh.

"Now, we need to strap you into the machine." Sunset pulled rubber gloves onto her hands, giving each a little snap before moving to help Twilight.

"You're sure this is safe, right?" She was starting to get a little nervous.

"I can guarantee that there will be no effects that last longer than a few hours at the absolute most. Now, I assume you've had sex before?"

Twilight blushed, not expecting such a personal question, seemingly out of nowhere.

"Um... yes, I have."

"Good, so you can probably tell what that dildo on the machine is for."

"I had a few ideas." Twilight rubbed her arms, now feeling even colder than before, despite the fact that her face had certainly warmed up.

"Well I need you to sit on it."

"Wait, what about the smaller rod? What does it do?"

"Oh, that one's a sounding rod. But don't worry, they're both plenty lubed up."

Twilight was sure that her face was as red as Sunset's hair by now. Nevertheless, she was still going to help Sunset. She made a promise, and she was going to see it through.

She stood over the machine, her legs on either side, and slowly began lowering herself down, using her arms as supports. When the first rod touched her, she momentarily froze up. She could feel how cold and wet it was. Sunset really wasn't lying about how much lube they had on them.

She took a deep breath. Come on Twilight, this isn't the biggest you've taken compared to your relative size, She thought to herself, we promised Sunset we would help, and that's exactly what we're gonna do.

Twilight continued lowering herself, the rod spreading her lower lips apart as it pushed deeper into her. About a quarter of the way through, she felt the second rod pressing against her urethra. It was even colder than the first rod. She had never done any sounding to herself, although she was aware of the concept. Twilight grit her teeth and pushed onward.

Every inch of the rods felt bigger and longer than the last. Twilight hadn't realized until now, but apparently human vaginas were smaller in relation to overall body size than a pony's was. Eventually, she did manage to reach the bottom, feeling completely stuffed on the inside. She could feel every bit of the metal rod, and just how cold it felt inside her. It took her a moment to catch her breath once she had finally bottomed out on the machine.

Twilight jumped little when Sunset grabbed her by the hand. Sunset threaded her arm through on of the loops of the harness, bringing it all the way up to her shoulder. She repeated the process with Twilight's other arm, and clipped together to two straps on the front, one above Twilight's breasts, the other below.

"Alright, that should keep you on there." Twilight started fiddling with the clips on the harness, trying to figure out how they worked, but couldn't figure out a way to undo it. "Sorry, but you're not getting out of that without a key." Sunset smirked. "Now for your legs."

Sunset put each of the floor mounted cuffs just above Twilight's ankles, clipping them shut the same way she had done the harness. Twilight had no doubt that she wouldn't be getting out of this on her own. She couldn't even close her legs because of the cuffs. As long as her knees were up, the most she could close them was at an 80 degree angle to each other.

"So, are you finally going to tell me what this experiment is about?" Twilight was desperate to know what she was about to go through now that there was no way out of it.

"This experiment is to test the effects of humanized Equestrian magic under stress and orgasmic pleasure."

"What?!"

"You're not having second thoughts, are you?" Sunset raised an eyebrow.

"Who, me? No, of course not." Twilight nervously looked around. "I was just curious, that's all."

"Okay then. Here, you see this remote." Sunset pulled a remote out of the pocket of her jacket, showing it to Twilight. She nodded. "This controls the machine your attached to. There's no way to turn off the machine without the remote. Once I turn it on, the dildo will start to vibrate, and it'll periodically get faster. The other rod will administer a small, steady shock from time to time. Those will also get progressively more powerful, but I promise they won't do any harm. After I turn this on, I'm going to leave. I'll come back every hour to check on you, but I'll leave the remote here. Those straps are elastic, but take a lot of effort to stretch. To get out of here, all you need to do is reach up here and grab the remote." Sunset put the remote in front of Twilight, but it was too far away for her to reach from where she was. Twilight's eyes widened slightly when Sunset reached a finger towards one of the buttons.

"Good luck." Sunset pressed the button, and Twilight immediately felt the effects. The dildo inside her spun to life. It was on what she could only assume was its lowest setting, so it didn't do much, but she could already tell that this experiment wasn't going to end well for her.

Just as Sunset was about to leave the room, she stopped.

"Oh, I almost forgot." She grabbed a camcorder mounted to a tripod that Twilight hadn't noticed before, sitting in the corner. She put it in front of Twilight and hit record. "Smile for the camera. Have fun."

Sunset shut the door behind her. There was no clock in the room, so Twilight had no idea how long she had been there when the vibrations suddenly got faster and she received her first jolt from the smaller rod. She could feel herself getting wetter and wetter, dripping her own fluids onto the machine that was torturing her. Her breathing picked up and she could hear little moans coming from herself.

She had to get that remote. At first, she tried slowly lifting herself from the machine, but the straps were to strong. She only succeeded in making herself moan as she slammed back down onto the dildo, unable to resist the pull of the straps for very long. She tried leaning forward, but she couldn't bend over far enough to reach it. Then, the machine got faster. Way faster.

The frequency of the shocks also increased. Each time, she could feel the now warm, but still wet, rod in her urethra start buzzing with electricity, sending fiery waves of pleasure up Twilight's spine, letting her feel it all the way to her brain. It was an intensely distracting feeling. Having a long dildo buzzing inside of her, soaking her inner thighs with her own fluid, all the while getting shocked to make it even more intense.

No, she had to focus. She needed to turn this thing off, and fast. Twilight could feel how close she was getting. She knew she wouldn't be able to hold on for much longer.

She pushed as hard as she could, putting all of her might into her legs. The device she was so desperately trying to flee from had other plans though. The strongest shock Twilight had felt you came suddenly and without warning. If she thought the last was powerful, this was a new level of pleasure and pain, and it was more than enough to send her cascading over the edge she had been so delicately hover on.

Every nerve in her body lit up, not just from the shock rod. She lost her footing and slipped all the way back down until she was seating on the device once more, both rods buried as far into her as they could go.

"Spike! Spike!" She cried out between her moans of ecstasy, "th- the remote! S-Spike! Get over here!" The machine was getting completely drenched in her fluids, her entire bottom was already wet from them.

"No way!" Spike's voice came from the hall. "You're doing that weird stuff again."

"Spiiiiike! Please!" She was slowly regaining her ability to talk in full sentences as the pleasure subsided and her orgasm faded.

"Sorry Twilight, but I can't let you do that." Sunset had returned, and she was eyeing Twilight with a stern glare. "The point of this experiment is to test your strength, not Spike's. Since I can't have you trying that again, I'll just have to take him with me."

"Sunset, please." The vibrations were getting so intense she could already feel another orgasm starting to build, and it was hard to focus on anything else.

"Sorry, but you already agreed to help and I can't have you messing up the results of your test. Come on Spike, let's go say hi to the other girls." Sunset stepped back in to the hall, shutting the door behind her once again.

"Okay. I can't wait to see what Pinkie's up to."

"No! Please! Come back!" Each word was punctuated with a moan from her rapidly approaching second orgasm. She had never come twice in a row this fast. Maybe if she could wait until right after her orgasm, when her mind would be at its clearest, she would be able to reach the remote. It was the only idea she had at the moment, so it was worth a try. Although, Twilight couldn't help but get the feeling she was running out of time to think of ideas.

"AAAAAAHHHHHHHHHHH" Twilight screamed out as she came again. She didn't know how many there had been, she lost count at 21. Without a clock, the only way to tell how much time had passed was Sunset's periodic returns to check on her. So far, she had returned four times. Each time she came back, she typed out a few notes on her computer, and then promptly left.

Twilight's mind was practically mush at this point. Her senses were dulled dramatically. All she could feel was the vibration and the shocks from the machine below her. Her nostrils were filled with the aroma of her own sweat and fluids, and her moans were the only sound that her ears picked up.

Each of Sunset's brief visits seemed to get farther apart, with each one having more orgasms in between than the last. Twilight knew there had to be a puddle of her juices on the floor around her, but she really didn't care. She had more important things to worry about with what little brain power she had left. She was down to one, final idea, and if it didn't work, she had decided that she would just sit back and enjoy the rest of the ride until Sunset was forced to let her out. Besides, she would have to let her go by Monday, so she would only be stuck in this infernal torment four two days at most.

Another orgasm was climbing towards its peak inside of Twilight, the shock rod making sure she felt every second of pleasure the vibrator was giving to her. She was going to use this one to her advantage though. All she had to do was use the adrenaline and the rush from cumming to push herself off of the machine and she could stretch the harness enough to grab the remote.

Well, it's now or never. She thought. She felt herself right on the edge of cumming and knew that if she didn't go now, she might never be able to escape. So, just as she came for what she hoped would be the last time, she put all of the strength she had to give into her legs.

She felt herself lifting off of the machine. Once the metal rod had slipped out of her, she knew her plan was working, she hadn't even made it that far yet. She used the rush of strength from cumming to push as hard as she could and she stretched as far as her arms could reach. She almost collapsed when she felt her fingers graze something plastic on the floor. Twilight wrapped her fingers tightly around it as she fell back onto the machine, both rods filling her holes up immediately. Fortunately, it didn't take a lot of mental activity to figure out what the big red button labeled "STOP" would do.

As soon as she hid the button, the machine that had tortured her, and forced to orgasm so many time came to a dead stop.

Twilight was panting like she had just sprinted a marathon without stopping, but her senses were starting to come back to her. Now that she could feel something other than the dildo in buried in her, she noticed something felt odd on the back of the remote. She turned it over to find a small plastic key taped to the back. It had to be the key Sunset had mentioned earlier, the one to let her out of the harness and cuff.

Sure enough, she found the slot for the key, and the clips popped open as soon as she slid it in. As she stood up, her she could feel how weak her knees were. All of her joints were sore, but after all she just went through, she could find it in herself to stand up.

She knew it wouldn't be a good idea to put on her clothes given how wet she is. Luckily for her, she noticed a towel sitting beside Sunset's computer. She must have brought it while Twilight was still basically brain dead and not noticed. It was a nice towel too, soft and white. She used it to thoroughly dry herself off before she started to put back on her clothes. She had only just managed to figure out how to put back on her bra when the door opened and Sunset walked in for the fifth time since starting the test.

"Hey, you did it! Congrats." Sunset walked to her camera and closed the side screen. She unhooked it from the tripod and put it in her bag beside the computer.

"Yes, I did." Twilight pulled her skirt up and zipped it tight. "And now, I'm never going to help you with anything ever again unless you tell me exactly what I'll be doing."

"Yeah, that's fair. But if I told you what you were going to do, you probably never would've agreed."

"Exactly!" Twilight opened her mouth to say something else, but just took a deep breath instead. "Where's Spike? It's about time we get back home."

"Oh, he went home without you two hours ago. He said something about his O&O group meeting." Sunset finished typing up her notes, and turned off the computer. "You should probably go though. I've got some cleaning up to do here, or else the janitor's gonna be furious."

Once she had her shirt back on and her bow tie clipped to the collar, Twilight left the school, returning to Equestria. She needed to rest after today, and Sunset couldn't blame her.

Sunset, on the other hand, had to pack up her machine and clean it before it would be ready for its next subject. She mopped up the floor and made sure to leave behind no evidence of what had happened today. Once she got home, she uploaded the recording onto her computer and watched it all in one sitting. She also may have pleasured herself a few times, but that's not important. What's important is that she now had all of this new data with which to further the cause of science for the good of humans and ponies alike. Now all she had to do was decide who should be her next test subject.

She eventually narrowed it down to one person. It would only make sense to see if they had different reactions to the same stimulus.

"Well Sparkle, I guess we'll see just how different you and the princess really are."

Author's Note

Go ahead and tell me what I did wrong. Yes, even spelling mistakes.

Also, tell me why if you disliked.