"You know, if you need a bit more time, I can always go for a walk and come back a bit later." Celestia watched as her student frantically moved around the large table with her newest invention on it for the second time, looking notably more flustered than she had at the start.

"NO!" Twilight whirled around with an oddly panicked expression before visibly calming herself and clearing her throat. "I-I mean, that's not necessary, Princess. I'm almost ready to start again."

"Are you sure? I promise you that I wouldn't mind. I haven't been in town for some time, and Ponyville always seems to have something new in store." She hummed. "There's no shame in it if you want to take a break, you know? I believe you that your invention was working before, but things like this happen to even the best ponies. Just a few minutes away from it might help you figure out what went wrong."

"I'm quite sure, Princess! B-but thank you for the offer. A-anyway, I think we can give it another try now, i-if you're okay with that."

Celestia frowned, feeling like that response had come a little too quickly. She did hope that her student wasn't catastrophizing the situation again. The poor girl looked like she didn't even want to meet her eyes, looking everywhere except at Celestia and trying to hide behind her clipboard. The princess shifted a bit in her thankfully comfortable chair, trying to appear more casual and relaxed to put Twilight at ease, only for her frown to deepen slightly as the motion elicited a squeak from her student and seemed to somehow make her even more flustered than before.
She quickly wiped the expression off her face before Twilight could get the idea that the frown was directed at her, instead giving her a reassuring smile. "I'm happy to start when you're ready."

"R-right." Twilight nodded, taking a deep steadying breath and focusing on her clipboard. "Okay, uhm, for the record, can you give your name and occupation?"

"Celestia Sol, Princess and Ruler of Equestria. And my date of birth is long before the introduction of current calendars, still." Celestia refrained from rolling her eyes as Twilight went through the list of questions again. She had enough experience with scientists to know that this was necessary, and it was at least less tedious than some court sessions. That didn't mean it couldn't get a little bothersome when an experiment required the same questions be asked again and again, though.

"A-and finally, uhm… i-if you don't mind answering. W-what were you wearing when you arrived here?"

Celestia blinked, surprised by the new and somewhat odd question that her student was visibly penciling in on her clipboard. "A long, champagne-colored dress with gold stitchings. One of Rarity's designs, I believe." She opted not to go into detail on her underwear, as her student already seemed flustered enough, nor did she ask why Twilight had to ask instead of simply writing down her own observations. She was sure there was a good reason that perhaps another scientist would recognize even without having it spelled out.

"R-right, a-and, uhm… w-where is that dress now?" Twilight was hiding her face completely behind her clipboard now, only barely peeking over the upper edge.

Celestia raised an eyebrow, before turning her head just in case this was some kind of trick question. But no, her clothes hadn't been moved. "It's over there on the table, along with my jewelry and my bra and panties." Folded up rather neatly, too, considering how many sad and dejected looks she got from her maid staff anytime she tried to stay in practice back at the palace.

"Y-yes, t-that is in accordance with m-my… my observations." Twilight squeaked and stammered, some literal steam rising over the clipboard as she ducked her head. "A-and, uhm, i-if you don't mind me a-asking, uhm… w-why did you take off your clothes and l-leave them, uhm, on that table?"

Celestia opened her mouth before freezing as she drew a blank. She knew there was a good and perfectly valid reason, but for some reason she could not think of what that reason was. "W-well, it's only polite not to leave a mess in somepony else's home." She gave a dainty cough to cover her embarrassment at having been caught out and needing to deflect like this. "And I took them off because…" She drew the word out, her thoughts spinning until finally she ~~came up with~~ remembered the answer to Twilight's actual question. "...because I was feeling too warm."

"Because you were feeling too warm," Twilight repeated, staring at her rather incredulously. "You, Princess Celestia, the alicorn who controls the sun, took off your clothes because you were feeling too warm."

"Indeed." Celestia smiled and nodded. Ponies wore clothes for insulation as much as coverage, after all, so taking some or all of them off because one was feeling too insulated was perfectly reasonable.

"And… you have no issue with sitting there completely naked, right in front of me, in the middle of the library?"

"Why would I?" Celestia needed to pause for only half a second to gather her thoughts this time. "The library is closed. And we've known each other for years, Twilight, for most of your life even. Even if I didn't trust you more than anypony else sans perhaps my sister, I'd say that between your various escapades over the years I'm hardly showing anything that you haven't seen before at one point or another over the years."

Twilight stammered and blushed at the compliment, turning around to run through a breathing exercise. Celestia shifted one leg to rest over the other and waited politely until her student turned around again.

"O-okay! I-I think I'm ready to… to try again now."

Celestia didn't voice that there wasn't really much of an 'again' yet, as she still hadn't actually seen what was under the tarp. Instead she leaned forward slightly with an encouraging smile. "You have my undivided attention, my faithful student."

Twilight muttered something that almost sounded like "that's what I'm afraid of", but before Celestia could ask about it her student gripped the tarp and pulled it off to reveal

"You know, I really won't mind if you need a break to check everything over. I could–" Celestia considered going out for a walk on the town before instantly dismissing the thought. "–look through your shelves for some interesting books. I don't get a lot of time to read things that aren't work-related." She'd probably have to be a bit more careful with the books than usual, too, but that was what magic was for.

"T-that's alright!" Twilight stammered, trying and failing not to stare at her. The poor filly could use a break in Celestia's opinion, looking awfully flustered at what to her mind must have been a string of failures.

"Are you sure, Twilight?" Celestia tried to put a touch of authority into her voice, but wasn't entirely sure if it came through in her slightly breathless cadence. "I'm not putting you at fault for anything, sometimes these things just happen. But you've aborted this experiment thrice now at the last second, and I still haven't even seen what's under the tarp. I'd much rather you took the time necessary to figure out where things are going wrong, rather than trying to brute force it."

"Ah, uhm, you see, t-the thing is…" Twilight squirmed and stammered, clutching her clipboard like a shield and her voice rising to a concerningly high pitch. "Y-you, uhm, you've actually, uhhhh… you've actually already seen what's under the tarp. M-multiple times, actually."

Celestia frowned in confusion. "I know I'm rather old by conventional standards, but I do believe I would remember something like that."

"Y-yes, uhm, normally you would, but… my new invention may have some… unintended side effects? I-it's, uhm, I think I told you about it at the start, did I tell you about it at the start? I-I don't know if I wanted to keep it a surprise or–"

"Twilight!" This time her authority came through clearly, thankfully, making her student lock up. "Deep breaths, Twilight, calm down."

"R-right, yes." Twilight took some shuddering breaths, a small bit of the tension leaking out of her. "W-well, it's uhm, it's supposed to help ponies with their focus, and be a study aid by letting them access more of their subconscious mind and, uhm… o-only I think it works too well, maybe? Because you kind of focused only on your subconscious and kind of a little bit… stopped being aware of things and thinking for yourself. And when I put the tarp back over it, you'd kind of retroactively blanked a couple seconds and forgotten that I pulled it off in the first place?"

Celestia raised an eyebrow at that. She did remember Twilight asking some odd questions the second time around that with context now made a bit more sense. Or they would, if Twilight was actually telling the truth, which she was still rather skeptical about. She would remember if she'd seen what was under that tarp before, she was rather certain of that.

"Yeah, uhm, I realized that that wouldn't really be very believable without some sort of evidence. So I went through the setup again and this time while you were staring at it I tried to make you write a note to yourself. That… didn't really work out either." She picked up a sheet of paper next to the tarp and held it up. It looked, generously and with supposed context, like the result of a unicorn holding a quill at the edge of their magic range and blindly trying to write words.
"So then I thought maybe if I could prove it some other way, by making you do something you wouldn't normally do, but I couldn't really think of any good options that would conclusively prove things even after you woke up again so, uhm… ImadeyoutakeyourclothesoffandI'mreallysorry!"

Celestia blinked, needing a second to parse that jumble of words. Once she did, though, she could only snort and shake her head. "You didn't make me take off my clothes, Twilight. I took them off because I was warm, remember? We already talked about this."

"Yeah, so apparently if you do something while you're in that mindless state, you subconsciously try to justify it afterwards." Celestia only just bit back another dismissive snort at Twilight's reasoning. "I hadn't expected that. B-but I figured maybe that was just because I'd underestimated how much you trust me and it was too easy for you to justify! So I tried to think of something else that you wouldn't be able to justify doing, a-and you were sitting there naked and…" She trailed off, looking meaningfully at Celestia.

Celestia stared back in confusion before looking down to follow Twilight's line of sight. At first she thought Twilight might be upset at just how bored she'd gotten of repeatedly answering the same question and was referring to the copious amounts of drool on her naked tits, or that her student was concerned about the way one of her nipples was starting to look a bit sore. But then she realized that Twilight's attention was actually even lower than that.

She gave an amused snort and shook her head. "Twilight, I can assure you that I am fully aware that I am masturbating. I don't think anypony could be oblivious to doing something like that." Just to prove her point she spread her legs to show just how deep her fingers were pumping into her dripping wet cunt, then gave her nipple another pinch and tug that made her bite her lip to keep from moaning out loud.

Twilight squeaked and hid behind her clipboard again. "A-and you don't see anything, uhm, o-odd about doing that r-right in front of me? I-in the middle of a library?"

"Of course not." Celestia huffed, her own face rather flushed at this point. "To be honest this is probably more privacy than I have in my own rooms in Canterlot. We're safely distanced from the bookshelves, and of course I will clean up after myself before I leave."

"Of course…" Twilight nodded with a thousand yard stare that incidentally went right across Celestia's chest. She swallowed heavily before slumping. "W-well, uhm… that is… to be honest, Princess, I'm at a bit of a loss. I really can't think of anything I could possibly do… or rather, make you do, that would convince you at this point. N-not without potentially causing a lot of questions from other ponies, at least."

Celestia rolled her eyes in amusement, pondering how to best reassure her student that she wouldn't hold a single, inconsequential failure like this against her. "Well, I know that one thing I definitely won't forget is that you are my faithful and beloved student. And I hope that you won't let a small issue like this make you doubt that fact, either."

Her student opened her mouth, then closed it again, blushing and twitching and making several aborted motions that made Celestia worry if she'd said something wrong, somehow. Thankfully, after just a few moments Twilight seemed to center herself again with a long exhale.

"R-right. Well, uhm, I somehow doubt that this will, you know… actually work, but I might as well…"

Celestia watched as the unicorn turned to the table again and grabbed the tarp, leaning forward as it was pulled away. Finally! Even if Twilight's project was a dud, at least she would get to see what all the fuss was abou

"Miss Spaaaarkle~! When do we get to see the big surprise?" Tia leaned forward while raising her hand, giving her teacher a good view of her chest and making her tits nearly pop out of the skimpy top she wore. Not that she was a teacher's pet (yet) or anything, but Miss Sparkle always paid her some extra attention when she acted cute and sexy.

Just as planned, Miss Sparkle's eyes jumped almost immediately down from her raised hand down to her cleavage, causing her to blush as she stepped closer to Tia's desk. "Oh? The big surprise was for the end of the lesson, Miss Celestia. Do you think you've learned everything you're here to learn?"

"Yuh-uh! I like, totally listened and paid attention and stuff!" Tia giggled and bounced excitedly in her seat. She may have gotten distracted a few times thinking about what the big surprise could be, but she totally listened to Miss Sparkle more than she did for any of her other teachers.

"Really? Well, if you've been paying attention then you shouldn't have any problems with a pop quiz, should you?" Miss Sparkle gave her a challenging smirk, walking over to the table with the big surprise and picking up a small remote and a long ruler she'd left next to it.

"Uh uhm uhh… n-not at all! I'm like, totally ready for a pop quiz!" Tia blushed and tried not to look too nervous, even as she stood up and pushed her chair back to get ready for the quiz. Her desk creaked dangerously below her as she leaned over it until her tits were hanging off the edge at the front, wiggling her butt for her teacher below the extra short miniskirt she was wearing.

"Well, that's good to hear. I'm sure you'll do just fine, then." Miss Sparkle hummed and walked up to Tia, looking down at her. "We'll start with an easy one. What are the three school rules?"

Tia perked up a bit. She totally knew that one! "Like, duh! Every student knows that one." She giggled. "Good students listen. Good students obey. Miss Sparkle knows best."

"That's right. I'm glad you've memorized the most important part of the lesson." Miss Sparkle smiled and pushed the button on the remote. Tia puffed out her chest proudly at getting the first question right, before letting out a moan as she got her reward for being a good student, bucking her hips as the vibrator in her pussy started to buzz.

Miss Sparkle held the button for a couple seconds before letting go. She let Tia slump over the desk to catch her breath for a moment before walking around to nudge her student's chin with the ruler. "Don't slack off on me yet, Miss Celestia. There's still a few questions to go."

"O-of course, Miss Sparkles!" Tia squeaked and quickly pushed herself up again, wiggling her butt to show she was ready.

"Very good. Now then, what is twenty-three times three?"

Tia froze with a squeak, pupils shrinking. Oh no, Miss Sparkle was asking about numbers! And not the nice easy numbers she could count on her hands, either. She swallowed nervously, giving her teacher a wobbly smile. "U-uhm, that's… twenty…six?"

"Oh dear, that's rather far from the mark I'm afraid." Miss Sparkle shook her head, moving back behind Tia and lightly brushing the ruler against her flank. "And you know what happens when you answer wrong."

"B-bad students get punished." Tia whined and squirmed, wiggling her butt.

"Indeed. Perhaps we can make it educational though. I want you to count along so you know exactly how far you were off from the right answer, alright?"

"Y-yes, Miss Spaaaaaah~!" Tia gasped and moaned as the ruler hit her butt with a loud smack. Miss Sparkle wasn't hitting her too hard, thankfully, each hit barely even leaving a mark, but after the first dozen spanks her white flanks were still starting to turn visibly red and sore, making her feel each following slap even more. By the time the last slap hit her flank, her admittedly rather thin panties were soaked through with arousal and the only thing keeping her from orgasm was that bad students don't get to cum.

Miss Sparkle stepped back around again, gently cupping Tia's chin with one hand. "And how much were you off the right answer, Miss Celestia?"

"Fuh-forty thu-threeee~" Tia moaned and drooled a little, wiggling her throbbing red butt as she looked up at Miss Sparkle.

"Good girl~" Miss Sparkle blushed and giggled before giving her a slightly concerned look. "Are you feeling alright, dear? If you'd rather break it off here…"

"N-nuh!" Tia scrambled back up to look attentive and ready. "I wanna see the big surprise! You, like, promised!"

"Alright, alright. I was just making sure." Miss Sparkle giggled and gestured for her to calm down. "I did promise the big surprise, once you've finished your pop quiz. There's only one question left though, don't worry." She straightened up and cleared her throat, blushing a bit. "The last question… what are you studying in my class?"

Tia blinked and stared back blankly for a second before she started to flush, panting and squirming in excitement as she happily gave the answer. "I'm studying to be a sexy, slutty teacher's pet for Miss Sparkle!"

Miss Sparkle blushed and giggled, holding up the remote teasingly before pressing the button with a teasing "Good girl, Tia~"

Tia gasped and moaned loudly, arching her back as the vibrator went on full power and immediately brought her over the edge, bucking her hips as she came hard. Her orgasm seemed to go on for minutes even though it was only a few short moments, leaving her once again slumped over her desk drooling and giggling.

"Such a good student~" Tia shivered happily at the compliment, slowly raising her head to watch Miss Sparkle walk over to the table and pick up a corner of the tarp. "Do you still want to see the big surprise?"

Tia perked up immediately, feeling her energy coming back at the thought of getting her promised surprise. She leaned forward, nearly toppling over the desk in her eagerness as she nodded excitedly. She watched as Miss Sparkle grabbed the tarp properly and yanked it off, revealing a

"You know, you still haven't shown me whatever is under that tarp."

"Oh? I thought we were doing something different right now, Celes– I mean, uhm…"

Sunslut chuckled as Mistress got mixed up with her 'public' name again. "Well, obviously, yes." She felt a light touch of Mistress' hand on the back of her head and obligingly leaned forward, diving back between Mistress' legs.
"I'm just saying… if you'd wanted me… to come down… from Canterlot… you could've just…" She dove a bit deeper, licking and sucking and coaxing a number of cute little moans from Mistress before she sat back again to give her a moment to breathe and pull herself together. "You could've just told me. There was no need to make up such an elaborate excuse."

Mistress gasped for breath for a moment before finally calming down again, still panting softly as she looked down at her. "And why do you assume that it was just an excuse, Sunslut?"

Sunslut shuddered, enjoying the way her real name in Mistress' mouth sent pleasure up and down her spine. She looked up at Mistress sitting on the edge of the table right next to her tarp-covered pretense. "Well, aside from the fact that I've been here a good while by now and you still haven't shown me that marvelous invention of yours? From everything you told me, calling just me for the presentation somewhat defeats the purpose, doesn't it?" She gave the unicorn a teasing smile and a wink. "After all, how would you demonstrate something that can put thoughts in somepony's head and make them obey your whims to your obedient pet slut who already does all that anyway?"

Mistress blushed and squirmed before straightening up a bit, holding one finger to her temple and opening her mouth. Sunslut saw her mouth moving, but all she could hear was soft static until Mistress removed the finger from her temple again. "Yes, exactly like that. Sunslut doesn't know what Mistress did, but Sunslut knows that Mistress doesn't need some silly machine to make Sunslut do whatever Mistress wants."

Mistress blushed and squirmed again before quickly reaching down and shoving Sunslut's head back between her legs. Sunslut giggled and got back to work, taking the cue not to stop until Mistress pulled her back again.

Of course that didn't mean that she couldn't cheat a little. Sunslut deliberately pushed a little deeper, getting Mistress closer to the edge before mumbling something that would be impossible to understand into Mistress' pussy.

A few seconds later she felt her head being pulled back again. She looked up with an innocent smile, delighting in the flustered glare that meant Mistress knew what she'd done, and that Mistress knew she had fallen for it anyway. "Could you please repeat that a little more clearly?"

"Sunslut only said, if Mistress' invention truly works like Mistress claims, Sunslut is surprised that you didn't invite Sunslut's sister instead."

Mistress stared in surprise, blushing and stammering. "W-w-what?!"

"Sunslut is just saying, if Mistress truly thinks her invention could do what Mistress said it could, Mistress could have tested it on Luna instead. It would certainly make Sunslut's and Mistress' meetings easier if Sunslut didn't have to make believable excuses to Sunslut's sister."

Sunslut giggled and leaned forward again to continue her ministrations on Mistress' clit. Of course the idea was laughable, but it would serve well to occupy Mistress' mind while Sunslut brought her to climax, and perhaps it would also make for a nice daydream to relax to when Sunslut had to take up her position as 'Celestia' in Canterlot once again.

Still no matter how smart and amazing Mistress was, some things simply weren't feasible. Like inventing a machine that would be able to rewrite somepony's mind, much less that of an alicorn. As Mistress grabbed her head again and bucked her hips to cum all over her face, she could say with absolute certainty that such a thing was simply a pipe dream, or her name wasn't Sunslut.

Author's Note

This one was inspired by Jukebox' (non-pony) story Out of Sight, Out of Mind and is going to (hopefully) be my longest entry in this event. That said, I'm quite proud of how it turned out.