By Moonlight

by The Delightful Goat

First published

In which one Royal Sister finds the other in a delightfully exposed position, and takes full advantage.

Princess Luna, after being denied entrance to her sister's chambers one lonely evening, breaks in to discover her in a delightfully exposed position. Taking full advantage, as is the only suitable thing for a sibling to do, Luna teases her relentlessly for her indiscretion, then, discovering that Celestia is nearly as lonely as she is, the pair enjoy a passionate evening together.

Written for the April 2019 Sibling Incest Contest.

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Princess Luna Narrates

“I… beg your pardon,” The white coated royal guard, a pegasus, said, trying and failing to put on the usual airs of authority and command in the face of my persistent, steady glare, “But The Princess commanded that she not be disturbed…”The guard pony finally trailed off as my eyes narrowed at him, his bravado not up to the task of turning away an alicorn princess several millenia older than he, and ended the sentence with a gulp, and a quiet, “Your… highness. N-Naturally we’d make an exception, but the door is locked from the inside, and it’s soundproof… Nopony dares interrupt Princess Celestia’s weekly meditations. Aside from breaking down the door, there’s no way for us to admit you…”

Stars and empty night, that’s the last time I let Celestia handle security, I thought to myself, fixing the guard with a flat look, then stepping over to the nearest window in the hallway, threw it open with magic, then leapt out into the soft tones of the summer night. I spread my wings to catch myself, remained visible just long enough for the Guards on duty to see, then, quite casually, alighted back down upon one of my sister’s many balconies several yards away. It’d have been too long of a leap for an earth pony, but, given modern Canterlot’s peculiarly ornate architecture, nopony had even bothered to grace the balcony entrance with so much as a door, much less a lock. It wasn’t even warded.

As per the common mode in the Royal Castle after dark, all was quiet and calm. While a year had passed since my return, now, and my own additions to the castle were beginning to take shape, my own… confidence, I suppose, was not nearly so swift in renovation. A thousand years in exile is not to be made up in a day, and, of course, while all proper appearances were maintained, it could be said that I was still somewhat unsure of returning to my old position. It wasn’t merely castle guards who looked at my restored form somewhat askance… if you can believe it, I actually overheard some ponies calling me cute, of all the absurdities, before I had fully adjusted to the world, again.

Just… go inside, and talk to your sister, Luna, I thought to myself, as I eyed the silken hangings that blew, gently, in the evening breeze, behind which were my sister’s private bathing area, cloakroom, study, and chambers. It’s not as though she’s going to send you back to the moon for interrupting her meditations… or even could, without the Elements, if she even wanted to.

I glanced back just long enough to see the pegasus guard squinting dumbly out the window, with a frown. The moon was scarcely half full, but apparently the light proved insufficient, and my dark cloak suitable camouflage, that I was as good as invisible even just a few short yards away… I allowed myself a moment of amusement at his confusion, as he shut the window behind me, then rolled my eyes… enough stalling already, Luna, and, putting on a casual posture, stepped through the draperies, albeit quietly. While, naturally, I could be as loud and commanding as need be, I was, naturally, also the princess of the night, and I could all but disappear into the shadows and the silence when so inclined. While it might have been more polite to announce myself outright, I opted for the stealthy approach… after all, if it turned out this wasn’t something I should interrupt, there was nothing stopping me from just…

Oh.

I had silently walked to the edge of Celestia’s bathroom, moving around the large, circular tub which had clearly seen recent use, and peeked around the edge of the door, into my royal sister’s bedroom. She was rather innocuously curled up on her bed, in the center of the room, but very clearly not asleep. Rather, she’d taken one of her pillows between her teeth, hugged it close to her chest with a forehoof, while the other slid… down between her thighs, slowly gyrating and grinding against both the pillow, and her right forehoof, causing me to briefly stare, then gape, then flush red and pink beneath my otherwise deep blue coat as I watched my sister playing with herself.

It’s not as though you couldn’t have seen this coming, my little pony said to me, from the back of my mind, ever the sarcastic tease, Though you’d almost think she wanted somepony to walk in and find her like this. If this is another of her infantile pranks…

“Oh…” Celestia moaned softly, past her mouthful of pillow, grinding with evident desire and sexuality into it, and, even as I watched, adjusting her position so that she was on top of it, and it underneath her, letting go with her mouth to sit back up and give a quiet but lusty whinny into the air… Oh dear.

She lent back down again shortly thereafter, her flowing rainbow mane and tail casting an interesting variety of beautiful shadows from the light of her fireplace across the room, itself quite dark, and I couldn’t help but creep inside, slowly, keeping to where I would be least easily observed… assuming my bright red face didn’t give me away, of course. My sister was actually clopping herself, with only a flimsy door and noise canceling enchantment between her and the entire world beyond! And assuming nopony so much as flew across her balcony, and got a peek at what she was doing.

In short order, I had made my way a third of the way around the outside of the room, keeping to the deepest darkness, and wrapping my star jeweled mane and tail around myself like an inky cloak, which rendered me as good as invisible in the gloom. Part of me insisted I set my loneliness aside, that being, whatever polite fiction I’d had in mind, what had really pushed me to seek my sister out only hours after sundown, but empty night would it be awkward if she realized I’d walked in on her in the middle of… enjoying herself, especially given the clearly shameless enthusiasm and affection she had for her sun embroidered body pillow, the lips of her vent sliding back and forth against it with each rotation of her hips.

She’d certainly have the embarrassment coming, after all the times I’ve been on the receiving end… I mused, inwardly, the beginnings of a prank gathering in the back of my mind, Maybe get her back for that time she dyed my mane and tail pink…

There was a certain voyeuristic thrill that came with watching my sister get herself off, her teeth clenched, her hungry moans moving back and forth between soft and loud at irregular intervals. Such a silly little pony she was… I started creeping slowly over, my hooves soundless against the marble tiles, even peeking out into the light, entirely unobserved, Celestia far too occupied with her own enjoyment than my approach. As I came finally up to the backboard of her round, ornate pony bed, however, she finally groaned, and made a decidedly un-princessly pouty face, and sat up, looking off to one side, and not noticing me. I was… relatively certain I hadn’t been caught, as my sister huffed to herself, rolled over with her back to me. From this angle, I was forced to twitch and stifle a laugh as I saw her start flipping through a copy of Wingboner Magazine, though I didn’t recall my sister being interested in other mares, before my banishment…

I could feel, as much as tell, when my moon came out from behind a thick patch of clouds, and briefly illuminate my elder sister’s bedchambers from above, through the domed skylight in the center, and, unconsciously, felt the need to be with her, which grew only stronger as she groaned again, and faceplanted down into the magazine, looking completely frustrated and unsatisfied.

Understandable, perhaps… My little pony said, from the rearward edges of my mind, You know how that is… it’s not as if the ponies of Equestria would accept just any pony, mare or stallion, as consort to a princess. Bucks don’t come any more esteemed than Shining Armor, and ponies were falling over from aneurysms when that wedding was announced… She looks… lonely.

Of course, it must have been hard for her… A thousand years with me on the moon, and Cadence otherwise occupied with her duties to the vanished Crystal Empire, until recently, but it just didn’t feel right that we, the rulers and protectors of Equestria, should be ever so alone… Which is why I gently nudged aside one of the pillows, and slid into the soft, plush bed next to my sister, as she went back to looking through the lewd images in the contraband magazine… Empty night, if one of the guards were to ever stumble upon that, the scandal would never end.

I saw Celestia perk, slightly, and the change in pressure on her downy bed, but it wasn’t until I lent in, and pressed my snoot into the back of her head, that she went completely still, and said nothing for several long moments.

“Sister?” The rainbow maned pony said, in a soft voice that I could only barely pick up, in spite of only being inches away. I opted to not respond to the obvious question… honestly, the fact that she was oblivious enough I’d gotten this far undetected was embarrassing enough, and she knew it, but that my touch could have been mistaken for anypony else’s was patently absurd. We, the Royal Sisters of Equestria, were thousands of years old, and knew each other practically as well as it was possible for two ponies to do so, in spite of my recent banishment. Perhaps she’d simply been… distracted. I leaned in closer, my hot breath on the back of Princess Celestia’s soft, white neck… she’d always had the nicer coat, damn her, and very gently reached up to put my hooves on her shoulders, and rub them tenderly, leaving my slippers behind on the floor.

“Yes, sister, you know very well it is I,” I said, as Tia turned her head slightly to see me, her mouth opening and closing several times, at a loss for words, as I nuzzled her, “Am I disrupting your… what was it, meditation?”

“I… well… Yes, sister, you know very well that you are,” She huffed, her cheeks gaining a delightfully strawberry coloration in the warm glow of the fire, “H-How long have you been here watching me?”

“More than long enough,” I said, with a dignified chuckle at my elder sister’s expense, and nestled up next to her, parts of me I’d never even realized were tense relaxing as we touched, our fur brushing together ticklishly, and the radiant heat of her body warming me… she’d always been like that. Warm. Welcoming. Comforting. The wisdom of the heart had always been her domain, and, like her sun, it was what warmed the hearts of all ponies, even, though I hated to admit it, my own. Celestia let out a very small noise that might charitably have been classified as a meep, and I saw her horn glow yellow, briefly, as she pulled the blankets over her magazine, cheeks going from soft red to crimson in a matter of moments, “I saw everything, Tia, you silly little pony…”

“I’m so much bigger than you,” She huffed, giving me a pouty expression that took me back millenia, and made me laugh as I embraced her, squeezing tightly, and remembering as I did times so far gone that they were the stuff of myth and legend, except to those of us who lived it. Soon, though, my sister relaxed in my arms, and I nestled closer, the heat of her body and mane like the heat of first light in summer dawn against my belly and loins, and it was all I could do to not start cuddling her on the spot, but, clearly, other things were on her mind. “You can’t know how I’ve missed this, Luna…” She sighed, leaning in and curling around to touch horns with me, and nuzzle properly. She smelt like fruit, and it made me smile.

“It wasn’t as though a thousand years passed in an eyeblink, on the moon,” I told her, dryly, and, experimentally, gave her a kiss on the nose, “Always the silly pony, you are. It’s why all the other silly ponies love you so much.”

Celestia snorted, and wiggled her nose around, giving me an equally experimental kiss back, more playfully than anything else, and grinned, “Some ponies are more silly than others. But… that’s not what I meant.”

“Does it have something to do with how playing with yourself, and looking at smutty naked pegasi mares now counts as meditation, Tia?” I asked, deciding I hadn’t quite met my quota of sisterly teasing, after her relative size comment, earlier. She blushed again, and pouted, adorably, as well.

“It’s not as though I can just grab up one of the castle guards, and tell them to get to work,” The rainbow maned alicorn said, rolling her eyes, “And, with the Crystal Empire gone, Princess Cadence has been too reduced or otherwise occupied to properly…” I put one hoof over her mouth, quieting her.

“You’re lonely,” I said, my eyes glinting with realization, as I slowly raised my sister’s muzzle until we were looking at each other directly, once again. She didn’t speak… but, honestly, she didn’t need to. I could tell by the way she didn’t move, or deny, or confirm anything. Her eyes… slowly welled up with tears, over the course of about a minute, and I had to shut my own, as well, to keep them from doing the same. Of course she was lonely… ours had been a lonely existence even before my banishment, and, I realized, she had been right that I couldn’t know what it had been like. I sniffled, softly, and lent into her, our quietly waving manes and tails waving in the currents of magic as they mixed, and said, softly, “I’m lonely, too…”

“Eep,” My sister said, her eyes widening as, very gently, I started sitting up, and rolling her over onto her back in the process, my own darkling form atop her. If this kept up, I’d have to get a bigger scroll for un-princessly noises my sister had made, today, but I was too busy suppressing tears at her obvious reaction to pay it any mind. “L-Luna, I…” She began, but I cut her off by leaning in quickly, and pressing my cool little pony muzzle to hers, kissing her abruptly and passionately on the mouth, and taking great delight in her shy little squeak. For such an outgoing and regal equine, my sister was remarkably easy to tease where this sort of thing was concerned. She flushed even pinker, the white of her face doing nothing to hide her rosy blush as she looked inclined to push me away, then, visibly, started to relax, leaning into the kiss, and returning it. Perhaps as I should have expected… Celestia tasted sugary sweet, our two bodies pressing close and intimate in an embrace, and, when I finally pulled away… I was smirking openly, and smugly, at my elder sister’s clear abashment, her ears laid back, her posture embarrassed and submissive.

“Now let’s see to… this,” I said, pressing my left forehoof against her chest, and holding her still, while my right squeezed down between us, and brushed against her moist inner flanks, my own starting to heat up rapidly after so much time pent up, as it were. I felt Celestia breathe in sharply as I found her moist and sun heated vent, and pressed the back of my hoof against it, sliding it slowly back upwards towards her tummy, and letting the soft fur of my legs do the work for me.

“S-Sister, are you really sure this is-” I cut her off with another kiss, deeply enjoying the feeling of Celestia’s clearly flustered form under me as I toyed with her, stroking my hoof back and forth over her sex, and making her wiggle in place.

“Now now, Tia, you’d think you hadn’t had sex in a thousand years,” I told her, smugly, as she writhed in place, making soft whining noises every time my hoof passed over her needy loins.

“T-That’s because I haven’t,” She huffed, but didn’t struggle. Neither of us had used magic, yet, but I was waiting for her to make the first move in that regard before I responded. Even as I watched on, though, her expression and demeanor changed from flustered and annoyed to deeply, desperately needy… we were still ponies, after all, in spite of our power and age. We still had a biological need for food, water, intimacy… sex. I could see the mingling irritation and desire flickering back and forth on her face as I stroked her already quite pent up and sensitive crease, deliberately holding back to make her want more, and lean in to get more out of what I was offering, which, bless her, she promptly did. “If anypony ever found out about this…”

“Perhaps you could send them to the moon,” I teased, leaning in and giving her a dominant nip on one ear, that earned me another squeak, “As always, sister, it seems up to me to ensure that your needs are met. Such a silly little pony you are.”

“I’m older than-” If she wasn’t going to learn, I’d just have to keep persisting. This time, instead of kissing her, I stuffed a pillow in it. Literally. I picked up a pillow, and put it Celestia’s mouth. The expression of scandalized frustration on her face lasted just long enough for me to scooch a bit forward, still on top of her, spread one wing, reach it down, and slide one of the long flight feathers right through her most sensitive of spots, then the second, then the third, and the rest of them, slowly, and causing the pillow in her mouth to abruptly become an asset, rather than an annoyance, as she bit down hard and started wiggling even more energetically.

“Oh, you’re older than me?” I said, batting my eyelashes at her, “I’d forgotten, since you hadn’t reminded me for a full five minutes. Now, would my big sister like me to go a little bit faster, hmm?” Celestia groaned, growing an even deeper shade of read, but having already begun to grind herself against my hoof, and my rump, and I could feel the subtle tug of her magic against it, trying to nudge me to go faster, “Now now, I want to have some fun, too…” I smirked even wider at her, then rolled over, still straddling her, but now with my rump, tail, and taint facing towards her head, and moistening with all the lust and desire in the air, “So if all you’re going to do is suck on a pillow while I toy with you, you might as well share.” She let go of the pillow, and I slid out lengthwise, my tail billowing out over her head, and giving her a face full of princessly posterior. She said… something, I could tell by the warm sensation of hot Celestia breath on my vent, and moaned softly in pleasure at it, but was too occupied otherwise to really pay much attention.

To give her the idea, and increasingly excited about the prospect of getting properly laid for the first time in a thousand years, I craned my head down, pressed my nose against my elder sister’s moist slit, and licked it from the top to bottom, breathing in her scent, and cherishing the soft whines and moans I could feel vibrating through her as I had my way. Any other intelligible words, following that, were reduced to soft whinnies and pleasurable sensations. Celestia even started getting into it properly, not long thereafter, and it became increasingly hard to concentrate on having fun with her snug, moist vent while panting from the touch of her tongue exploring me in return. I abruptly became very grateful for Celestia’s minimalist security, and the audio reducing enchantment, given the amount of lusty noises we were both making, especially when my turn to squeal came, and I felt something soft, thick, and firm begin to spread my vent wide, strong and unexpectedly.

“T-Tia…?!” I gasped, my body going rigid, and my attention to her sex ceasing as I peered back over my shoulder, only to see my sister’s horn glowing bright sunny yellow, and a similarly colored aura of pure telekinetic force, in the distinctive shape of a large equine cock, being slowly pushed inside of me, spreading my sex wide, and sending me into a shivering, whining heap on top of her.

“You started it, little sister,” Celestia mused, smugly, as the heat and pressure of being filled by the magical stallion phallus pressed deeper and deeper into me, banishing all conscious thought briefly in the sheer intensity of the sensations, the sun fire warmth of her power, the pressure against my insides, the teasing slide of the conjured toy against my clit. After hundreds of years without sex, it was enough to set me so far back on my heels that I wasn’t even able to suitably respond until Tia shucked me out of my revelry by beginning to stuff me properly with the toy, moving it in and out, and forcing me to gasp and pant with each thrust. “You always were such a delightfully sensitive little pony…”

“O-Ooohh…” Was all the response I could make, my eyes practically rolling back into my head as every thrust sent me deeper and deeper into the shivering wreak-world of near orgasmic bliss. It was the sort of deep physical intimacy that you simply couldn’t get, easily, in our position… but at least we could always be there for each other. As my body began to quake, I started reaching out and gathering magic to my horn, as well. Explosively horny as I was, I couldn’t quite manage the delicate balance of girth and ridges my sister had put into the construct with which she was now pounding my parts, but… In her state of sheer arousal, I didn’t need to be a master sculptor of cock in order to get the desired result. My will shaped the ambient magic into a rough phallic shape, and, entirely unannounced to my sister, who’s concentration was on driving me crazy with need, at the moment, I pressed my own transparent toy, made of cool starlight and the deep marine blue of my magic, against her moist sex in reply. “G-Gotchya.”

I felt Tia’s breath quicken, and watched in curious fascination as I willed the toy forward. Partially transparent, I could literally see into her quivering vent as the toy I’d created spread it wide. I could feel her own conjured form quivering inside me as she fought to maintain it’s specific dimensions and that, at last, was what pushed us both over the edged. Our bodies shuddered as though the mountain beneath the castle was shaking, and our whinnies and moans were probably audible even through the stained glass and door hangings. The pleasure of an intense, radiant orgasm shot up my spine like a jolt of electricity, and, when it faded, I collapsed, panting, my vent squarely atop Celestia’s nose, my own face pressed between her thighs, and completely exhausted. Both toys dissolved, the magic keeping them animated dissipating back into the ambient mana, and leaving my sister and I sharing her bed, softly panting to ourselves, and remaining like that for several minutes.

…”Sister?” Celestia eventually said, as the intense, but subtle afterglow of our sworded afair continued to fade. I blinked, and peered over at her, and she continued, “Why… is there a letter in your hair?”

“There isn’t,” I blinked at her.

“There is.” Celestia repeated, and I did indeed feel something pulled from my waving mane. A letter, as she said, which promptly unrolled itself in front of her, “Dear Princess Celestia. La la la, visiting Canterlot, would love to see you tonight, urgent business, will be flying in, Princess Twilight Sparkle?”

“When did that come in?” I said, realizing that we, somehow, must not have noticed during our… excitement.

“She could be here any moment…!” My sister gasped, and started wiggling underneath me, the pair of us somewhat tangled in her covers and pillows, only to be… abruptly distracted by the loud pop, just outside, on the balcony, which sounded a great deal like somepony teleporting in…

Princess…es!?” Oh for the love of the stars…

“Does NO PONY knock, anymore?!”

The End