>You are princess Celestia.
>This was going to be interesting.
>You walk down to the sub-levels of the castle.
>Only guardsponies knew of this level.
>They were the only ones that really needed to.
>Another left and you were at the door to the dungeons.
>A lone guardspony watched the door.
>”Good afternoon Princess.” He says with a bow.
“Good afternoon guardspony…?”
>”Garrison, mam.”
“Ah.  Has the watch gone well?”
>”Nothing to report of note, princess.”
“Good.  I need to access the dungeons and be sure to keep my whereabouts secret.”
>”Absolutely, princess.”
>He opens the door and you thank him.
>There were many cells down here.
>Not many have been actively used in ages, though.
>They’re kept clean just in case.
>At most they’re used to scare petty thieves and house the occasional drunk until they sober up.
>But this…
>This was a special occasion.
>It was imperative that the cell you were looking for was secure and nopony knew of its…occupant.
>Another minute of walking, and you’re there.
>You open the door to a pitch black cell.
>No windows, no candles.
>Just stone and chain to keep “him” secure.
>A crystal adorns each corner.
>With a cast of simple magic, they illuminate the cell completely.
>There “he” is.
>This creature that only you and Luna knew about, that was kept in a cell that all others were strictly forbidden from entering under the guise of contamination.
>You’re clever if nothing else.
>You were loose with designating it as a he, if only because you could see his maleness, being stricken of his clothes.
>But otherwise, he was something to be feared, at least until you could “coax” information out of him.
>Which brings you to now.
>This was not something you had done in over a millennia, but you knew what to do.
>The worst part was…part of you looked forward to it.
“Arise.”
 
http://www.youtube.com/watch?v=BHRyMcH6WMM (if you'd like)
 
>He looks up at you nonchalantly.
>And does nothing.
“I said get up.”
>You cast you magic on his chains and tug them.
>You couldn’t affect him directly, or this would’ve been taken care of already.
>No, you had to be creative with him.
>And you loved it.
>Magic sometimes was so passé.
>To have to think outside of the box, as they say, was invigorating.
>He was shackled just above each hand and just above each foot.
>The chains were long and slack, so he could move if he so pleased to a point.
>But he just sat there defiantly.
>The tug, however, managed to send the message.
>As he stood up fully, you have to steel yourself not to step back.
>He was certainly a large one.
>In fact, it was one of the few times you had to actually look up at another standing individual, albeit slightly.
>One reason you feared him, just because of his size and seeming ignorance of magic he could be a serious threat if he so chose.
>The other …
>”Hello Celestia.”
>His tone.
>It was ice cold.
>He showed no care whatsoever for your title or that you controlled his fate.
>If he would at least divulge more about himself and not act so imposing, you would be more than happy to give him a chance.
>You smack him with a fore hoof.
“You will address me as –Princess- Celestia.”
>He turns his head back slowly, grinning all the while.
>”But of course….Celestia.”
>You hit him again, harder.
>Normally you’d be concerned using such force and seriously harming another.
>With him, it didn’t seem to have any noticeable effect.
>A chance to cut loose.
>He still grins.
>You return the gesture.
>Oh how you’ve wanted this.
“You realize you could make things much easier on yourself if you simply cooperated and gave me what I asked, yes?”
>”But what fun would that be?”
>He wanted fun?  
>Best not to let him down.
>You grab the chains with magic and force them to pin him to the wall splayed out.
>Next you grab a whip that was placed on the wall next to the door.
>A favorite of yours.
>It’s been some time since you’ve used it, you hope you aren’t out of practice.
>You lash with it using your telekinetic grip.
>A light welt appears across his chest.
>You haven’t forgotten.
>As if it was only yesterday that you brandished it.
>He winces ever so slightly, then smiles.
>”Now we’re talking.”
>Surely he did not…
>Very well then.
>You lash three more times at various points on the torso.
“Is this fun for you still?”
>The marks are there, just as his smile.
>Another few strikes.
>He reacts to all of them, but not how you want him to.
>One more crack catches him across his cheek.
>That did away with the smile.
“I thought you might not enjoy that.”
>You smirk.
>Then he chuckles.
>And turns his head.
>”Oh don’t worry princess, I’m more than capable of turning the other cheek.”
>He’s sick.
>But that means more fun for you.
>You let the tension off his chains.
>He takes a step forward.
>This creates enough of a gap from the wall.
>You lash the whip out, but this time you let it wrap a few times around his neck.
>And yank him stumbling forward to his hands and knees.
>Not giving him a chance you bring your front hooves up and press them on his back.
>He’s lying flat on the floor now.
>A much more fitting position.
“See? That wasn’t so hard.  I knew I could break you in and teach you manners.  I mean, prostrating before the princess?  How endearing of you.”
>You shift your weight a bit onto him more.
>Then you step back with one hoof and keep the other slack on his back.
>He attempts to push himself up slowly, but you cut him off by putting a firm hoof on the back of his head.
“Ah ah ah. You’re not done yet showing your reverence toward me.”
>You dangle the hoof in front of his face and remove your cuff.
“Why don’t you put that sharp tongue of yours to actual use?”
>He stares at your hoof, then slowly grabs it with a hand and begins to lick it.
>Impressive how quickly he catches on.
>He licks the front, around the lip, and underneath all in one motion.
>This is quite nice, you’ve not had this treatment before.
>It’s a shame he’s too dangerous to release, he would make a fine pet.
>Then again, pets should be contained…
>You grin widely at this thought as he continues to slather your hoof.
>It’s disgusting thinking about how his drool coats it, yet arousing that you’ve reduced him to this.
“What a good boy.  You know, if anything you should thank me for allowing you the privilege of sampling me like this.”
>He laughs.
>”I’ve ‘sampled’ better from garbage cans.”
>Oh he will pay for that.
>You quickly press the hoof into his skull and force him to the floor,
>A few good turns should drive the point.
“Insolent welp! I could crack your skull and think nothing of it.”
>”Were it so easy…” He says through gritted teeth.
>You let off of him.
>As he gets up, you notice that member of his has become taut and rigid.
“Well despite your best efforts it seems your little ally has betrayed you.”
>”Don’t flatter yourself.”
“Drop the charade.  It’s obvious to me that you have become enamored with me. “
>You turn around and take a few slow steps forward and sway your hips as you do.
>That should be far enough.
“Come and get me…”
>He roars out.
>His fingers come within an inch of your flank.
>However, the chains hold fast at their maximum length.
>He strains and grunts, no doubt wishing to tear into you, but not out of passion.
>You taunt him.
“I thought you wanted to make me your helpless little prey, but I guess I was mistaken.”
>A buck from your hooves stammers him back a few steps.
>You snap the whip around just above the left foot and pull his leg out from under him.
>He lands hard on his back.
>You take this opportunity to stand over him, clasping the chains down so he can’t move as you straddle him.
“You pathetic gnat!  You honestly believe I would let you simply take me?  What makes you think you are even worthy to look upon me, let alone touch me?!  I should snuff you out right here. It’s only fitting that you should have to look upon me from such a lowly position.”
>You let off the magic and place a hoof on his throat.
>He clasps it with his hand.
“Beg me for mercy….”
>He gnashes his teeth and mutters something.
>You lean closer.
“What was that?  It sounded as though you wished for me to end you.”
>He mumbles again and you lean closer.
>”…Gotcha…”
>You can’t react as he’s too fast and strikes your horn hard with his other hand.
>The sudden jolt sends a shock through your body, only to be interrupted by a jerking motion from your leg.
>His other hand clasped firm, he pulls you in close.
>An appendage places itself on your chest.
>You’re sent flying back against the wall by a powerful thrust of just one of his legs.
>By the stars, where did that strength come from?
>Your horn struck the wall as well, inhibiting you from using your magic to restrain him.
>You hear him strain and look to see him furiously pull on his on chain.
>What a futi-
>It snaps at the wall.
>Perhaps you should have had those checked…
>He looks at you with a menacing smile.  
>You rise up to meet him, but before you can cast, he whips the chain at you and wraps it around your neck.
>He’s manic.
>Oh dear…
 
 
>You are Anon.
>And you’ve always wanted to do this.
“GET OVER HERE.”
>Yanking the chain hard reels her in toward you.
>She has no time to react as you wrap your arms around her chest and heave her into another wall.
>She yells in pain, but this was only the beginning.
>You pin her hard to the wall and grab her horn so that she can’t teleport away.
>She is upright, thus giving you all the leverage over the slender pony.
“Well now isn’t this an interesting turn of events.”
>”Release me you cretin!”
“Oh nonono, I couldn’t do that, I haven’t had my fun yet.”
>You sniff her from her chest to her neck in one long huff and shudder.
“That stench…so delicious…is that fear I smell?”
>”Better than you smell…” she says with a defiant grin.
>Your smile wraps around your head as you pull her from the wall, turn her, and slam her stomach against it.
>You spread her legs to lower her slightly and line your throbbing erection with her vagina.
>You whisper gently into her ear.
“This will not be over quickly.  You will not enjoy this.”
>Her eyes widen slightly then completely as you enter her hard.
>You thrust slowly but methodically in and out.
>She is yelping and grunting with each push.
“You whorse, you’re enjoying this aren’t you?”
>”Now who’s *hrk* flattering *hng* who?”
>You laugh and continue to work.
>”You were…right about one *gasp* thing.  This is…this isn’t enjoyable….Imeanhonestly *squeak* is this the best you can do?”
>Unfortunately for her, no.
>You tighten your grip on her horn and pull her head back.
>Next you take a finger and trace her puffy little pucker and she shrieks.
“Take a guess where he’s going?  I’ll give you a HINT.”
>You jam two fingers into her butt.
>She wales like a banshee.
>You work her over and over and over, her legs giving out long ago and you alone supported her.
>The fingers give you the leverage that you need.
>The floor is practically flooding below you two.
>With one gloriously hard thrust, you cum fully into her.
>She moans and you let out a guttural roar.
>Your legs lock and you both pant, using the wall as support.
“…Flawless victory…”
>You’re about to address Celestia when something catches your peripheral vision.
>Princess Luna and Twilight Sparkle are standing at the open doorway.
>You and Celestia look like deer in the headlights.
“Uh………It’s exactly what it looks like.”
>Luna speaks
>Oh crap…
>”And just what in TARTARUS IS THAT?”
>You and Celestia both wince and whine at her voice which reverberates off the stone.
>”Luna… please not so loud I thought we went over this?”
>”Sister, you currently have the human Anonymous buried in you twice over, yet you wish to speak to me about formality?!”
>”Th-that’s not the point! What are you two even doing here???”
>”We WERE looking to get your opinion on one of Starswirl’s research notes and when we could not find you, we asked the guards until we came upon the guardspony Garrison.”
>You whisper to Celestia.
“I thought he was going to keep your location a secret?”
>Luna cuts off Celestia as she tries to address you.
>”When a guard is questioned by royalty of equal stature, they are expected to br-WILL PLEASE YOU REMOVE YOURSELF FROM OUR SISTER?!?!”
>DAMN that’s loud!
>You quickly tug yourself from Celestia with two audible pops, followed by the splashing of sex on the ground.
>Luna looks away in disgust while you two dust yourselves off.
>”….w-wha..”
>You forgot about Twilight, whose mouth is agape with tears in her wide eyes.
“Twilight, uh, I can explain.  You see, uh… well the princess here…we were talking an-“
>”-I wanted to get to know Anonymous better, s-so we met in priva-“
“Simply to talk.  Just.  Talking. But then we grew….”
>”Closer and found that w-we…we had things in common and I had a…a favor…to ask.”
“One thing lead to another...”
>Twilight is still speechless so Luna speaks up.
>”And you came *hurk* to the dungeon because?...”
“….It’s kinky?”
>You both squee.
>You didn’t know you could do that.
>Luna shakes her head slowly and turns around.
>”If you’re finished …can we please just purge this moment entirely and work on these notes?”
>Celestia and yourself can’t speak fast enough in agreement as she levitates your clothes over and you dress yourself.
>Twilight stutter steps around and woozily begins to follow Luna.
"Oy vey that was awkward.  I didn't even hear them come in."
>"Neither did I. I knew I should've just teleported into the dungeon."
"Oh well, could've been worse."
>"How so?"
".....Maybe not...."
>"For what it's worth, that was simply incredible."
"I know right?  I'm sorry if I got too rough there, I didn't think I'd get that into it."
>"No no you were fine, great even.  I loved how forcefully you took control."
"I was just ad-libbing honestly, I wasn't sure how rough I should be.  How's your neck?"
>"A little sore but it'll be fine. And yours?  I hope I didn't hurt you with my hoof."
"Nah it was good, I can't believe how much I was enjoying that though."
>She smirks at you
>"I'll have to remember for nex-"
>"WE CAN STILL HEAR YOU!"
>Jeeze...
>You both quickly catch up to them in awkward silence.
>It’s practically painful.
>Poor Twilight.
>You and Celestia exchange glances, blushing feverously, but she nods for you to console Twilight.
>You reach your hand down to pat Twilight’s head, she usually likes that.
>Unfortunately it was also the same hand that you went turd spelunking with.
“Twilight I-“
>”AHHHHH! AH AH AH AHHHHHHHHHHHHH!!!!!”  
>She snaps her head away and bolts off.
>Right into a wall.
>She’s out cold with a thud.
>Celestia is mortified and you feel terrible.
>Luna looks at you both, then Twilight, then you again deadpanned.
“I-I’ll get her…”
>You pick her up under your other arm.
>Celestia smacks a hoof to her face.
>Next time you’re locking the doors yourself…