Proof of Concept

by The Cloptimist

First published

Princess Cadance has some ideas to spice things up in the bedroom with Shining Armor. She wants to test them out first. On you.

When asked what he'd like for his birthday, Shining Armor has let slip he has a thing for dominant mares in latex. Princess Cadance is game, but feels a little unsure of herself, and doesn't want to mess up Shining's "present". Luckily, she knows you - her sister-in-law's coltfriend - share the same tastes, so she decides to test the waters with you first...

Shameless second person clop, featuring latex suits (obviously), teasing, very mild tentative femdom, and lots of looking long and lovingly at perfect pink pony princess posterior.

NB - this story takes place in the same timeline as Cause and Effect and Test Drive, but the characters aren't anthro here, because, uh, reasons.

Show and Tell

View Online

The Crystal Empire is a nice enough place, all told, but it's not home.

For one thing, it's bigger than Ponyville. The buildings are taller here, the houses are all angular and sharp; nothing like that at home between the crazy assortment of cottages and thatched roofs, at least until Twilight's castle appeared. Coupled with the big, paved streets, hard and slippery under your hooves compared to the comfy grass and dirt of home, it always felt a bit too clean here, a bit too cold. And this huge, skyscraping crystal castle isn't really helping.

The other reason you always feel out of place here is that ponies won't stop staring at you.

You try and hide behind your newspaper as yet another family slows to a trot as they pass, gawping at you, trying to work out where they know you from.

The newspaper has an article about Spike, "by the ponies who know him best!", apparently. You don't recognise any of the names, and you know Spike as well as anybody; you saw him this morning, in fact, slumped on his back, reading a comic, and eating cereal directly out of the box. Oddly enough, none of that seems to have made its way into the article, which makes him sound like a grizzled war hero.

But much like "Spike the Brave and Glorious", as the paper calls him, you're more famous here than you are at home, albeit for different reasons; you've been officially dating Twilight Sparkle for a few weeks now, but the news hasn't spread far, and the only times you've been out in public with her have been up here.

You look up from the newspaper to find another crystal pony staring at you, until you make eye contact with her and she quickly scurries off down the hall.

You know Princess Cadance pretty well now, too; she and her husband have been nothing but welcoming since you first met, and you hit it off pretty quickly. They made jokes, listened to your stories, covered up faux pas and awkward silences, helped you past your initial nerves dating a princess and a celebrity.

You've even been snapped by the crystal paparazzi having lunch with Cadance or Shining Armor when Twilight herself wasn't present; they're a fun couple, and they're nice ponies, and the truth is, you'd probably enjoy hanging out with them even if you weren't dating Twilight.

All that said, it was still a surprise to get a scroll from Cadance asking you to come up to the Empire and meet up with her. It was even more of a surprise when, having travelled all the way up here and arrived at the palace, you'd been left waiting in the hallway for... what is it, nearly an hour now? And still no sign of her, or anyone coming to get you. You're kind of tempted to approach one of the crystal guards and ask what's going on, but you don't really want to draw more attention to yourself. Besides, you're tired from the trip, it's good to just sit down and rest your haunches for a while, even if you'd rather be doing it at home.

More time passes. You're thinking about re-reading that Spike article, or going over the hoofball results again, when there's a murmur of anticipation, and everypony in the hall turns to face one way.

Princess Mi Amore Cadenza appears, and time seems to pause for a moment.

She's flanked by her two almost ever-present bodyguards, burly, bullet-headed crystal ponies you've seen - and played cards with - a bunch of times before. But you aren't looking at them.

The light from the windows and the shimmering crystal walls is shining directly upon her like a spotlight... or like she herself is glowing, radiating a soft, pink light throughout the huge room.

Damn, she's beautiful. You'd never say this out loud, of course, but she really, really is. And she's incredibly nice, too, patiently talking to each of the dippy tourists and petitioning locals who've approached her since she came in, never a hint of boredom or impatience, giving some kid her hoofprint on a picture, always smiling.

If Shining Armor wasn't such a nice guy, and if you didn't have your own beautiful princess waiting back in Ponyville, you'd be jealous. As it is, you can only acknowledge the objective fact that Twilight has an extremely attractive sister-in-law.

She sees you, and you'd swear her smile just got that tiny bit bigger as she turns to trot towards you, her bodyguards gently clearing a path for her. They're both smiling too; you bet she tells them to do that.

"Anon!", she beams, and trots over to you, as you stand up and give her a formal bow. She giggles.

"You don't need to do that, you know. I never ask anyone to bow. But it's very sweet, all the same."

It's true, she's never asked. It's something she insists on not doing, one of a whole series of tells to help identify her as the real Cadance, some of which are open secrets, and some only her guards know about. She knows she can't be too careful, and she's got good reason given the horrible things that happened to her in the build-up to her wedding - but she's never let it affect her, she's still the same sweet, trusting, happy-go-lucky pony that Twilight tells you she always was.

Some of the guards - heck, some of the old nobility of the Empire, too - don't seem very happy to have a Princess who talks so openly with her subjects, or who disdains royal protocol, or who'll happily break away from an official function to play with a bored foal. But the ordinary crystal ponies love her, these two guys are cool, and Shining Armor is always there to keep the others in line when it comes to his awesome wife.

"Now, come with me," says Cadance, still beaming, and she sounds... nervous? Excited? You can't tell. "I've got something I need to talk to you about."

And with that, she turns tail and starts trotting back to the exit, guards in tow. You shrug, and follow her; Stout Shield, as you know the guy on the left to be called, helps motion some bystanders away as they watch you trotting off with the Princess, and realise why they recognised you.


"Uh... so... what's going on, Princess?", you ask.

"How many times, Anon," she giggles from the next room. "We're friends. Call me Cadance."

"Um... okay? Cadance?"

This is all getting weird.

The guards had left you both in her suite, in a little state room with tables and chairs and tea and biscuits, somewhere you're guessing she hosts informal meetings with other dignitaries.

Literally as soon as the guards left, Cadance had fixed you with a determined look, just waiting for a moment, without saying a word. She'd looked at you in such a strange way, like she was sizing you up or something, and the silence had gone on long enough you were about to say something, when she'd asked you to go and wait in her bedchamber instead, to "make yourself comfortable in there", with no explanation.

You were going to question it, but she'd given you another one of those winning smiles, and, oh well, whatever. She'd then pranced off to another side-room, and left you alone, again.

At least this time you can still talk to each other, not that she's answering any of your questions.

"It's nothing!", she says, from behind the door. "I just, well... I have an important job for you. I wanted to get your... opinion, on something."

The door opens, and Cadance walks out. You look up, expecting to see whatever it is she wants your opinion on, but... Huh. If she was doing anything in that other room, it's not obvious; she's not carrying anything, her hair's the same, she's wearing the same golden horseshoes, collar, crown, same makeup, nothing seems different.

"Uh, Princ- I mean, Cadance? What is it?"

She flinches for just a split second, and you're not sure if her smile vanished for that moment there, because as soon as you notice she's right back to normal. Still, she takes a deep breath before answering.

"You'll see, Anon. Just, um... Promise me you won't... No, you can't promise that. Look, just wait there for a moment, alright? I'm... sorry to be vague like this."

Her horn glows, and you hear the outer door of the suite locking. You look over to the door, and back to Cadance, but she's disappearing behind a large dressing screen at the far end of the bedchamber.

What is happening?!

You try to process what's going on, but your bewildered brain can't produce any further helpful thoughts, just a continuous loud whistling noise.

You hear noises from behind the screen, but you can't really work out what they are. Okay, that was one of her golden horseshoes hitting the floor with a deep, sonorous clunk. Followed by Cadance cursing under her breath. But the rest of the noises, no idea. Is she going to model some new shoes for you, or something?

...What is happening?!

"You see...", comes Cadance's voice, a little out of breath. "Shining Armor's birthday... is approaching..."

She's clearly struggling physically with something. That last word sounded like she had something gripped in her mouth.

"...And he's made some... Argh, come on!... very, um, specific requests about... Ugh, why won't this bucking thing tighten?... Um, about what he'd like for his present... Ah, there we go!"

Some new clothes, maybe? It could even be some... special clothes? Ugh, you feel bad just thinking that. You don't know each other that well. And surely she's got plenty of female friends to talk about that stuff with, and...

Cadance pokes her head around the screen and looks directly at you, stopping your chain of thought. All you can do is stare back, and hope you don't look too stupid.

"...And I need some help. A second opinion. Maybe... maybe even some..."

...her voice tails off, getting quieter and quieter as she reaches the end of the sentence...

"...practice...?"

You tilt your head at her, waiting for her to step out from behind the screen, or at least explain what in Equestria she's talking about, but she doesn't; she bites her lip, and looks nervous again. You decide to try and put her at ease, even though you're not the one acting strange. She's obviously really worked up over something about this present.

"Relax," you chuckle, giving her your best attempt at being breezy. "Shiny's a good friend, and so are you. What do you need help with? If there's anything I can do to help, you know I'd do it."

You meant it, too, as you smile in (what you hope is) a reassuring manner.

"Plus, my train back to Ponyville isn't for another few hours yet, so, y'know, no rush..."

Cadance looks at you, looking up and down, before apparently making a decision. She closes her eyes, lets out a breath, and steadies herself before continuing.

"Well...", she says, and her voice takes you by surprise, suddenly forceful and imposing. A tiny hint of nervousness, quickly squashed down.

"First of all... There's this."

Her hoof emerges from behind the screen, shrinkwrapped tightly in... shiny black latex?

"After Shining's... request, I asked around, and got it made to order by an excellent designer in Ponyville... It really is a wonderful outfit, you can hardly see a single seam..."

She wiggles her foreleg, showing off how the light shines off the slick, polished rubber.

"...But I'm just worried I'll look ridiculous. What do you think?"

She steps out from behind the screen, and you see it's a one piece, form fitting suit, all four legs, hooves, and her body encased in skin-tight, black, glossy latex, up to her long, graceful neck, where she's still wearing her royal collar... while her tail swishes free behind her, and her wings extend and contract through two neat holes in the back, twitching slightly, unfurling and folding with each deep breath she takes...

"...Do you think I look ridiculous?"

She strikes a pose for you, while looking in your eyes.

You let out a gasp, which came out sounding rather less manly than you'd hoped, but she doesn't seem to mind. You're pretty sure you're blushing, hard. And speaking of hard... you're almost immediately at full mast, the shock and surprise and just plain weirdness of the situation apparently no match for the fact that one of the most beautiful, kind and famous ponies in all of Equestria is standing in front of you in a black rubber catsuit.

Keep it together. She wants your opinion. As a friend. Maybe she doesn't realise how inappropriate this all is.

This must be a dream. Maybe it's a spell. Maybe she's a changeling. Maybe she's reading your fucking mind, since this is one of your biggest fantasies, and you've certainly never talked to Cadance about it, but...

Oh, she's so beautiful. And that suit...

Fuck.

Say something. She's looking at you. Say something. Right now.

"I, uh... no! It looks totally amazing... I would love to see Twilight in... that...!"

Really, that's what you went with? Smooth. You try and play it off with a soft chuckle, but really, you're still a blushing mess, just sitting there, staring at her amazing body, with your erection bulging up and flaring out and just being completely undeniable.

"...If, uh, this is what Shining wants... for his birthday...?", you stammer, your mouth going dry. You wait for confirmation, or permission to continue, or any kind of response, but Cadance is just... looking at you, and so you try to fill the silence up with more words.

..."If you go all, uh, dominant on Shining, and you're dressed like that, I'm pretty sure you could just say a few words, or pose for him, and he'll just.. burst..."

She's still looking at you, and now she raises an eyebrow. But she doesn't say anything, so you keep on talking.

"...Trust me. He won't be able to stop..."

You're just muttering to yourself now.

"Same with me, though... but, well, uh, you know..."

You're aware your voice tailed off there, as your eyes drifted to her rump, and your brain thankfully decided to cut you off before you made things any worse.

Cadance glances down at your increasingly difficult to ignore cock, now well out of its sheath and throbbing helplessly in the air, and makes some kind of mental note of the effect she's having. She smirks, pretending to be coy as she finally responds in a playful voice.

"...Oh, so you think he'll like it? I was a little worried about the way it makes my rump look..."

She turns around and wiggles her rear, giving you a perfect view of her ass, with the suit clinging to it, outlining every curve, defining each taut, quivering cheek as the light shines off the smooth, rounded surface of her rubber-covered flank...

"But, if you like it, well..."

She swishes her beautiful tail from side to side, giving you a fleeting glimpse of the neatly cut hole in the back of the suit, and what lies underneath, taking a step or two backwards while she swishes it... as you get a nose full of her scent...

"...Well, maybe it does work after all..."

With an audible snap, she wraps her tail around one of her hind legs, and you see her neat, taut little lips, shivering even though it's hot in here, and catching the light... a glistening, sticky royal marehood, inches from your face.

"... And you're not just... saying that... to please me?"

You can actually feel yourself blushing... or maybe that heat is coming from somewhere else, as you look at her gripping her leg with her own tail, and then gaze straight into her dripping marehood, not more than maybe a foot away from your face. If there was a line to be crossed, you've gone far past it already. You start actively wanting her to go further... what if she'd stroke your cheek with that tail, or your chin, or your... You can't even complete the thought, as you feel your cock throb in agreement. Seeing Cadance like this has you harder than you've ever been in your life. And then you realise she asked you a question, and she's waiting for an answer, standing there with her almost-bare rump almost-touching your face.

"No.. no! I say it because it’s true...! Uh..."

You've come this far, it's not like you can somehow make it worse now. Might as well go for it.

"...I mean... if it was me... a magic job, or something to tease him? Like... before you get to the, uh... real fun? That would... that would do it for me, I mean..."

The scent of her marehood, and the fact this is actually happening, is making you light-headed. You gulp, taking the humid bedroom air into your dry throat.

"Oh! really?", she smirks - you can hear it, even though you can't see it. "So, if I was to, say... push him down, like this...?

She flexes her hind hoof, stretches out her leg and plants it firmly on your chest, and gently but insistently pushes you back into a more reclined position.

"... And maybe if I said something about, I don't know..."

She clears her throat, and adopts a deeper, more strident, more commanding tone of voice, something like her aunt's Royal Canterlot Voice, just - thankfully - a lot quieter...

"Your Princess is deeply aroused, and demands you help her out RIGHT NOW..."

...a giggle, her latex-clad rear hoof still pressed against you...

"...something like that, hmm?", she giggles, back to regular Cadance again, seemingly utterly at ease with the whole situation.

Which is more than you can say for yourself. You gasp again, staring up at her... her perfect ass, her hips, her everything, up towards her face, your arousal just getting worse and worse.

"Y-yes," you stammer, forcing the words out past your lack of breath. "Something like that... or maybe about how, uh... 'your princess is deeply aroused and demands a plaything'... you know... being... dominant?"

She hasn't touched you, and yet you feel like if you possibly get any harder, you might end up cumming right there and then.

"...And if you want the night to last... you could cast a spell on him...? Like, an endless orgasm spell... then you can, uh, play with him and make him cum as much as you want... and... he will..."

Cadance keeps up the pressure with her back hoof. "... Such a lot of interesting ideas...!"

You can only stare as her tail unwraps itself from her suit, and raises up in the air again, the pretty colours a stark and beautiful contrast to the shiny black rubber.

"... And if I were to demand a... a plaything, did you say? What should I do with my tail, do you think?"

She swats it gently across your face, just barely brushing your nose.

"I mean, this suit does make your Princess rather... sweaty... But I know some men really like that, mixed in with my... intimate scent... Are you one of those?"

She pushes her rump back a little more, and swishes her tail all over your face, chin, neck, nose, mouth...

"Does Twilight do this for you, I wonder?"

You notice her wings are stretched out, fully erect, and suddenly feel something warm and tingling around the base of your shaft, gripping it firmly - but so softly! - while tiny sparks of magical electricity stimulate you.

"...Or this, maybe?"

The magical field envelops your whole cock like a hundred moist kisses, as you feel her real hoof, warm latex, pushing against your balls.

"... Don't hold back now. It's very important your Princess knows just how you really feel..."

You groan, loudly. You're not going to give her an answer, and you figure she doesn't expect one. Instead, you just moan as her magic expertly strokes you off; you're not going to last much longer.

And she knows it.

"That's it, that's my big, strong stallion...", she coos, her voice shakier now as she embraces her role. "Ooh, I forgot how much I love this spell... Oh, yes, good boy..."

Suddenly, her voice goes full Luna; bold, and resounding, and... dominant.

"Your Princess approves very much..."

She's unashamedly jerking you off with her magic, your cock luxuriating in her spell as she massages your heavy balls with her hoof...

you're going to cum

"Mmmm... I believe there's something in here that belongs to your Princess. Give it to me."

...faster and faster stroking, and...

you're going to cum on Princess Cadance

"Right now. All over my royal rump. Do it."

...presenting herself as a target...

you're going to cum on Princess Cadance and there's nothing you can do about it

"DO IT!"

You gulp for breath, and that's as much as you can take, as you roar in satisfied triumph, feeling yourself burst...

...watching in slow motion, as each scalding jet of cum sprays across that astonishing princess rump, on her suit, on her skin, in her tail, on the floor...

Cadance doesn't miss a stroke, calmly tugging you to completion as the orgasm tapers off and the final pumps squirt themselves out of your exhausted cock. She slowly finishes stroking your balls, and then trails her hoof up your sensitive shaft, collecting up the last dribbles, the stray globs of cum... then you see a glow of magic, as she wipes up the mess, and... oh, Celestia, did she just put it in her mouth??

"Well!"

She turns to wink at you, in more ways than one.

"Mmmm. Yes," she says to herself, with a huge smile. "Yes, I think you're right. I think this will definitely work."

She looks right at you, fixing you with a stern expression.

"Your Princess thanks you for your assistance," she announces, trying not to giggle as she does her best impression of Princess Luna. "You may, um, use the royal bathroom to clean up some more, if you so wish."

Leaning in close, she whispers softly in your ear, and nuzzles you tenderly.

"Thank you, Anon... It's alright. I promise."

You just lie there, basking in the glow of one of the best orgasms of your life, and wondering what the hell just happened, and what's going to happen now.

"Shining won't mind... he'll be grateful you've convinced me to try this with him for real..."

She gives you a hug, the latex of the suit hot to the touch against your chest. She giggles.

"...And if you want to, I'll tell Twilight where she can get one of these outfits too!"