Meanwhile back in the palace.

Luna and Celestia playfully circled one another trading verbal barbs as their eyes locked. “So my pastry obsessed sister, how did you manage to pick your oversized rear off the ground so soon after I put you on it?”

Celestia didn’t cease her predatory circling to answer. “Hmmm… All it takes is one slip up, a simple lapse in focus, and you’ll be all mine, my little sister.”

They continued to dare one another to make the first move so they could dominate the slower pony.

By this point the musk and pheromones hanging in the air had become so thick and powerful that many guards and staff had begun rutting each other's brains out in every possible combination of gender and position. Thankfully by tradition, palace staff were mostly unwed, ensuring no loyalties outside of the crown. Which meant there was little chance of marriage vows being shattered this day (Cadance would have been devastated).

The palace halls quickly began to fill with lewd moans and the slapping sounds of sex. A few mares and stallions left out of the orgy simply saw to their own needs as they could do nothing but stare at the dance playing out before them.

Celestia and Luna hardly blinked as the orgy broke out around them, instead they continued to stare deep into each other's eyes and circle the room. Ultimately it was Luna, distracted by the growing need in her core, who blinked and looked away, but only for a second.

Celestia seized the moment, she dove forward and gripped Luna in her magic, being rough but not enough to hurt the smaller alicorn. Celestia tsked. “And now you’re all mine, my little pony.”

Luna did her best to look mad rather than horny as Celestia practically pranced into the magical circle towing Luna along in a golden glow of magic. Luna couldn’t remember the last time she had seen Celestia this giddy, and it would be heartwarming, if not for the fact it was her loins that were warming instead.

Now standing within the circle Celestia gently sat Luna down near one of the central runes. Their “battle” finished, they both knew it was time to begin casting. Bright gold, and cool blue light began to flow from the horns of Equestria’s rulers as liberal amounts of powerful alicorn magic flooded into the magical pattern beneath them. It responded by pulsating with golden thrumming bursts of light humming loud enough to be heard throughout the room. Celestia and Luna now concentrated entirely on their channeling, all other doubts were pushed aside as they knew where finishing this spell would lead them.

Luna tried to will the magic out of her horn faster, she was once again dripping with need from her rear as she waited for the magical circle to charge so they could begin the ritual.

Celestia, her massive cock slapping against her muscular barrel reminding her of what was waiting, called upon her awesome reserves of willpower and focus, allowing her to ignore her mating instincts as she weaved her golden magic carefully into the final bits of the spell circle. She would not risk this failing; Luna after all these years deserved to be with foal and if Celestia’s massively swollen testicles were any indication, Luna would not leave wanting.

As if sensing their urgency, the charged spell circle flashed brightly.

Celestia gasped as she instantly felt the change throughout her very being. Her entire core thrummed with powerful energy as her life essence and mana pool connected directly with the sun itself. Light enveloped her, so bright that Luna and the nearby guards had to look away.

As the flash subsided, Celestia could be seen standing tall and proud, taller in fact. The spell pushed her very being so far beyond its normal limits that Celestia’s very frame had grown to accommodate the change.

Now nearly a foot taller and more muscular, Celestia looked every bit like some star-born goddess. Her multicolored mane and her powerful wings were now imbued with a small outline of dancing flames that licked and jumped in the cool castle air. Her normally pristine white fur was now slightly tinged orange, giving her an almost tanned look. However, it was her eyes that seemed to call the most attention. Where once before sat eyes that would meet any ponies gaze with a gentle purple that called forth memories of matronly love, now set two blazing stars, filled with strength, determination, and indomitable power. Before Luna was not Celestia, but the awe-inspiring Sol Dominus.

Luna had seen the ritual countless times before, so it shouldn’t have shocked her, but having those intense eyes drill deep into her with such hunger made Luna involuntarily shiver and gulp. Regaining her senses, Luna did her best to continue the ritual.

Clearing her throat Luna found her voice and remembering the ancient words spoke, “Celestia, First of Equus, I, Luna, pledge my life and womb to the service of Equestria, may my offspring bring joy and laughter to all who meet them. May their honesty drive all lies from our lands. May their kindness and generosity inspire all ponies to better themselves. May their loyalty carry them through hardship. And together with all ponies, may their innate magic spread harmony so that Equestria may always prevail.” Luna finished her lines and bowed her head waiting for the response.

Nodding with satisfaction, and perhaps a bit of over-eagerness, Celestia answered Luna’s pledge. “I Celestia, first of Equus, recognize and accept the pledge of Luna on this day. May her and all of Equestria be blessed by the miracle of life given here.”

Next she turned to all in attendance. “As is tradition during these celebrations, all children conceived on this day in our presence shall receive my blessing, and all expenses related to their upbringing shall be covered by the crown.”

She smiled at all the guards around her as they stared up at the star-goddess in pure awe. “Now, join me in this celebration of life! Under my sun, be fruitful and multiply!”

After saying this, a pulse of magic shot out of her horn; every mare and stallion within earshot instantly had their fertility pushed far beyond the normal limits. If this was anything like celebrations of the past, many mares would soon find their bellies carrying twins or even triplets. Overcome once more by everything going on, groups of guards, palace staff, and even the occasional Canterlot citizen formed around the castle in every mix of stallion and mare and began rutting each other in a near fever-pitch.

Celestia smacked her lips in satisfaction as the fresh orgy began throughout the palace, the incredible lust and love spread pungent smells throughout the halls that Celestia breathed in deeply. She had greatly missed these moments of unrestrained passion. As in centuries past, many bonds formed here would be bound in a miasma of magic and love that made them all but unbreakable. There would be few “one night stands” among these lovers.

Turning her fierce, hungry gaze back towards Luna, she found Luna’s own piercing blue eyes locked on her shining with their own unrestrained need. Both lovers smiled as they slowly approached one another, Luna gave a sarcastic curtsy that caused Celestia to aggressively bump her with her huge flanks.

This caused a cry from Luna as she attempted to right herself, only to be enveloped in Celestia’s wings and warmth once more. The seemingly flaming tips of Celestia’s wings and mane did nothing to harm Luna, instead tickling her fur and causing her to laugh into Celestia’s chest fluff. Luna finally looked up into sister’s face, which was now much higher above her than before. “We fear that in our hurry to find… er relief, we have become most uncoordinated.”

Celestia smiled warmly down at her even smaller sister. “Then we shall be your rock to find balance upon, shall we begin, dear sister?” There was no need for a reply, their lips met in a passion filled kiss as they simply melted into each other.

Somewhere just outside the palace.

Canterlot was engulfed in unrestrained pandemonium. City guards ran back and forth trying to wrangle citizens into designated evacuation zones while pegasi flew overhead providing cover. Nobles stood around the grand gate of the palace, loudly demanding to know why they had been locked out of the day court, all while haggard guards tried to pull them away.

An angry looking earth pony mare with a shaved mane and numerous scars walked through the mayhem. A nearby unicorn was scanning random civilians with a changeling revealing spell and the mare stopped for a moment as she was hit with a green flash, shivering as the magic moved over her fur but did nothing more. Nodding in satisfaction the unicorn moved on to a new group as the severe mare made her way to the middle of a large gathering of soldiers.

Stomping a hoof and hollering to get everyone’s attention, the gruff earth pony immediately began shouting off orders to the various groups. As the well trained soldiers shifted into their positions, She gave a grunt of satisfaction while she waited for the Elements of Harmony to join them. She certainly didn’t like the idea of risking some of the most valuable citizens in Equestria along with a freshly minted princess, but it wasn’t her job to question her orders, especially not in a time like this.

Not long after the air *popped* as Twilight, her friends, and the accompanying guard ponies materialized near the gathered forces.

A few spears were aggressively lifted, but soon went back to neutral as many gave a small bow to the Princess of Friendship. The scowling mare saw the group arrive, and approached. The earth pony stopped just before Twilight, giving a short bow toward her and the celebrated elements.

Twilight blushed, she was still unused to receiving so much attention from so many ponies. Twilight pushed down her discomfort and studied the mare for a moment, she reached deep into her vast repertoire of knowledge until she remembered a name.

“Thank you for organizing our forces so quickly in response to this grave crisis, General Comet. Your actions during the Storm King’s invasion saved countless lives. I have no doubt you will bring that same tenacity to our current predicament. Please update me on the situation, if you will.”

General Comet nodded before responding, her voice raspy. “Of course your majesty, you honor me with your compliments. Currently we’ve assembled an elite strike team mostly made up of veterans from both the changeling and Storm King invasions. These ponies are very comfortable with pitched urban combat and I believe they are our best chance of breaking this attack.”

Excellent! Twilight thought to herself, Pony soldiers rarely see combat these days, so veterans of two major conflicts may just give us an edge on our attackers… if only we knew who or what our attackers were!”

“General, do we have any indication of who or what has invaded our nation’s capital?”

General Comet shook her head. “None your majesty, we’ve seen no signs of combat outside the palace or in the surrounding city that would give us any indication of what we’re dealing with. We’ve also been purposely avoiding any areas that would allow our attackers to spot us from inside, hopefully protecting our element of surprise. However, this means we have little intel of what’s happening inside.”

Twilight frowned as she was absorbed in troubling thoughts. Suddenly her mood was broken when Applejack put a reassuring hoof on her shoulder, “Don’t worry sugarcube, if anyone of these ponies here is smart enough to figure this dirty mess out, it’s you.”

Twilight nodded weakly, she knew she had the smarts, but wasn’t so sure if the bravery would follow.

Suddenly everypony's attention was captured by a fast flying brown pegasus that landed nearby, completely out of breadth, but clearly beaming excitedly, the pegasus quickly trotted up to the general and the Princess.

The pegasus took a moment to breath, while General Comet introduced the newcomer. “This is Captain Rapid Arrow, he’s leading one of our fastest pegasi scout groups.” The general waited a few more moments before finally directing her attention to the exhausted pegasus. “Captain Arrow? Report.”

Captain Arrow did his best to stand upright, still smiling he swung a hoof up in a short salute, “Ah general, you should have seen it! Our boys are up there all guts and glory, like a fine oiled machine-”

The general suddenly cut him off with a growl, “I want an update, can you stick to the point, Captain?”

Captain Arrow gave a sheepish grin and cleared his throat. “Uh, right well you see, our boys are pretty good and pretty sharp, they going in barreling low, getting in so low,” he spread out his wings crouching low to the ground to demonstrate. “oh it's a sight to see General! Gliding in fast like that toward Canterlot, throwing the grass and the chickens right out of their wake!”

A sudden look of realization dawned on Comet’s face and she grabbed the Captain by his shoulders and shook him while shouting, “Where are they heading captain?!”

The Captain shot a confused look to the General before answering. “They’re geared for a crash insertion Ma'am, right through the palace windows of course!”

General Comet quickly turned to Twilight. “Your majesty, we need to get inside NOW!”

Celestia and Luna were almost one body as they intertwined each other sharing sweat, body heat and saliva, they had been passionately embracing and kissing for what felt like hours as their breaths came in labored gasps. Pulling their lips apart, Celestia and Luna looked deeply into each other's eyes. Luna let out a sudden yelp as Celestia grabbed around her with powerful hooves and hoisted them both into the air with a beat of her large wings. Celestia hummed with satisfaction as she began to line Luna up. Sensing what Celestia was doing, Luna began to relax into her sister’s powerful grip and did her best to align her rear with Celestia’s throbbing head.

A tinge of fear flowed through Luna as from this angle and closeness she could now see just how massive Celestia’s flare was, it was dotted in small bumps and had an almost sun shaped ridge around the tip, in many ways matching the owner’s cutie mark. The rod of flesh beneath it was also a sight to behold, almost glowing with magical power, it pulsed with Celestia’s own heartbeat.

Luna let out a breath she didn’t know she was holding and looked back up to Celestia, nodding in acceptance.

Celestia smiled as she saw her younger sister overcome her hesitation; she would do her best to remain in control and go slowly so as to not hurt the smaller alicorn. Pushing her hips upwards she gently lowered Luna down, until the head of her massive cock sat just outside Luna’s folds. A liberal spray of precum squirted from the tip, causing Luna’s folds to flicker open and her own large clit to wink uncontrollably at the sudden stimulation. Celestia’s pre was so warm it heated Luna’s hind legs as it dribbled down, causing Luna to loudly moan.

Celestia tensed, giving herself a moment to maintain control upon hearing her sister moan like a whorse. Taking a deep breath, she slowly, painfully slowly, pushed her throbbing head into Luna’s tight folds causing them to part. A liberal amount of lubrication and marecum sprayed on Celestia’s tip as she pushed, ensuring Luna would feel little discomfort. Soon the head popped inside and both Celestia and Luna shared a throaty moan.

Celestia didn’t stop there, slowly pushing her way inch by inch as her massive rod failed to yield to Luna’s clenching walls. Lightning bolts of pleasure shot through her as Celestia’s massive head scraped her sensitive walls, followed by a pulsating rod of flesh, radiating heat born from within her larger sister’s own core.

Luna was beginning to lose her thoughts, her sharp mind in shambles as pure pleasure and bliss threatened to turn her into nothing more than a drooling ragdoll. Her entire being felt enveloped by Celestia’s burning body heat and all throughout her insides Celestia’s thumping heartbeat was carried into her by the massive multi-foot cock that now pierced her innermost being.

After what felt like hours of slowly inching forward, Celestia was forced to come to a stop by a barrier that would not yield to her massive cock head. I’ve reached Luna’s cervix! The thought itself filled Celestia with even more need. She knew she would overcome that barrier soon, as she had more than enough length to push past it, but for now she chose to pull Luna up while pulling her own hips back, causing a whine to escape from Luna’s lips as the massive rod of warmth left her clenching pussy.

Celestia leaned her head down and whispered huskily into her younger sister’s ear. “Fear not Lulu, my warmth will not leave you.”

To emphasize the point, the solar princess slammed her muscular hips upward driving her massive cock back into Luna’s depths. Luna let out a satisfied moan as their bodies rejoined, and Celestia began to repeat the process faster, driving Luna down on to her while motioning her hips upward.

Despite the great strength and focus required to both hover in the air and engage in such tiring activities, Celestia barely felt winded, empowered by the mana flowing through her veins and the lust driving her muscles into incredible feats of endurance. She was no longer worried about hurting Luna, such was the lubrication coming from the blue alicorn, joining her own precum as it practically gushed from the tip of her flesh spear. So Celestia began to pick up the pace, grunting in satisfaction every time she felt her head smash against Luna’s innermost barrier.

A loud smacking began to overtake the other sounds of lovemaking throughout the palace as Celestia’s massive balls smacked against the flesh of Luna’s taught rear.

As if in response to this increase in speed from the Sisters, many of the nearby participants redoubled their own efforts, smashing their hips into one another, swallowing deeper, or flicking their tongues farther into their partner’s depths. A cacophony of moans quickly began to join the sounds of the Sisters’ own love-making as they smashed their bodies together in an almost violent display.

Celestia, hearing the cacophony of moans around her let out a joyful cry. “Do you hear them, Luna?!" Luna and Celestia began their own veritable chorus of shared moans and cries, Celestia’s hips now thrusting so quickly and deeply into her sister that her motions were but a blur to any observer.

Luna for her part could do little but hold on and match her sister’s moans of pleasure. Her depths were being absolutely obliterated by Celestia’s solar rod, but she didn’t care, there was little pain. Her entire being had become nothing but the continuing ebb and flow of a great, pleasurable pressure and heat, like the pulsing core of a star. Her mind was like a narrow tunnel now; only focused on the sensations within and nothing else.

Celestia began sweating profusely as she continued pounding into her little sister. She wasn’t growing tired, but the tingling sensation within her signaled that their joining was soon to come to an explosive end. Celestia’s grin grew feral as she pulled Luna even tighter to herself, she would soon claim her sister’s deepest depths and pump a life into her!

Letting out a wild cry Celestia bit down possessively on Luna’s neck, causing Luna to shudder and yelp spraying even more juices around Celestia’s burning rod.

Celestia didn’t stop, instead she let Luna slide down farther than she had since they began. Finally with a herculean thrust, Celestia pushed her massive cock head through Luna’s deepest barrier, penetrating her cervix.

Luna cried out in a mixture of pain and pleasure at this intrusion into her very center. Celestia held Luna in place as her massive balls bucked into her scrotum, a rumble foretelling their imminent release. The rumbling was so powerful, it caused Luna to shake slightly as she whimpered in a mixture of fearful anticipation and heat-driven need.

Celestia didn’t release her tight grip, nor did she let Luna’s nape out of her possessive bite. Instead she pushed her hips solidly upward, ensuring her cock made a tight seal within Luna’s depths. Beating her wings harder they both carried higher into the air, the massive magical circle beneath them began glowing with a sense of finality.

After what felt like minutes, Celestia’s shaft began to widely buck and bulge within Luna. Luna cried out once more as Celestia’s already massive flare grew even larger within the entrance to her womb, sealing tight and ensuring not a single drop of the coming flood would escape.

A large bulge traveled up Celestia’s girthy shaft, reaching the tip and positively gushing into Luna’s waiting womb. The incredible warmth of Celestia’s thick seed quickly painted Luna’s insides, causing her to lock up in a powerful orgasm that blanked her mind. Luna’s hind legs kicked empty air as she nearly passed out from the sensations flooding into her.

Celestia however, was nowhere near done. Like an unleashed firehose, her stallionhood absolutely flooded Luna’s insides, each powerful pulse of her throbbing cock pushed more and more life-giving essence straight into Luna’s womb. Celestia’s massive flare stopped most of the flood from escaping, quickly causing Luna’s belly to distend like a late-term pregnancy.

Celestia released Luna’s neck from her teeth as she cried out in joy, feeling her sister's belly press against her own as it grew. “Yes, Sister!” “Bring life into my kingdom once again!” She pumped her hips forward even more pushing her head even deeper into Luna as she still continued to pump her essence into Luna’s overfilled womb.

Luna at this point was being wracked with endless orgasms as the warm pressure in her depths pressed against every sensitive nerve. Drool flowed from one side of her slack muzzle as she faded in and out of consciousness. She could hear her sister shouting something nearby, but it sounded so muffled and fuzzy that she gave up trying to understand it and simply let the warmth carry her into a dreamless slumber, a goofy smile plastered across her face.

Celestia finally felt her incredible orgasm ebb and then stop completely as the last globs of thick seed pushed their way into her positively overfilled sister. Grunting in satisfaction, she slowed the flapping of her powerful wings and gently brought herself and her swollen younger sibling back to the ground.

With great care, Celestia began to withdraw her softening cock from Luna’s depths, as each inch of flesh crept out of her sister’s folds, a splash of almost glowing semen spilled to the floor below wafting steam into the air as it cooled. Each drip that left her sister’s insides was like a painful sting to Celestia; she wanted, no needed, to make sure this mare was with foal. Celestia thought to herself. Perhaps just to be safe we can go another round later?… Or 3…Her cock finally slipped free with a slobbery plop as it swung back beneath her.

Celestia gently placed her sister down near the middle of the circle, the glow of the spell warmed the marble, eliciting a happy coo from the blue alicorn as she tucked herself into a fuzzy bundle, her wings instinctively wrapping around her swollen belly as she slept.

Celestia beamed happily at the wonderful sight beneath her. Whereas Luna had left Celestia a sweaty, quivering mess, Celestia had left Luna warm, and full. Master of the carnal arts my prodigious flank, Celestia thought smugly to herself.

Soon Celestia’s thoughts turned toward the future, she could see Luna prancing around the Canterlot gardens, a beautiful foal giving chase, no several, no now a dozen, the image shifted in Celestia’s fantasy as soon dozens of their adorable foals chased Luna around the palace.

Celestia’s soft member quickly became rigid again as her thoughts drifted towards making the dream a reality. She began absentmindedly stroking her quickly hardening cock with a wingtip, eliciting a happy groan from her muzzle. As Celestia’s pace quickened she stared down at her sister’s massive belly, thoughts of doing this to Luna again and again and again filled her mind. Celestia began to openly pant and growl, thinking about how many foals she’d make the small alicorn carry for her.

“Yes!” She cried out, her wingtip now an absolute blur against her throbbing pride.

Suddenly a loud -crash!- echoed throughout the palace. All three of the already damaged western-facing windows exploded inward tossing shards of glass in every direction. The spell circle reacted instantly; flashing as a protective barrier shimmered into being, it stopped the glass missiles before fading again.

A squad of pegasi wearing sleek metal armor smashed into the marble floor, scattering bits of glass with their hooves as they came to a skidding stop and drew intimidating looking crossbows.

Adding to the sudden mayhem, a loud pop filled the air, and Twilight, her friends, and an entire army of pegasi, unicorns, and earth ponies all heavily armed and armored suddenly materialized in the throne room’s entryway.

It was at that moment, glass falling around her, Celestia peaked, and an impressive liter of semen flew like a gunshot into the air…

And smashed directly into Twilight Sparkle’s face.

Several seconds earlier.

Twilight sparkle’s entire world slowed as she materialized into the throne room, she did her best to quickly take in everything around her, noticing to her dismay that the palace windows had already been smashed in, bits of glass still raining down as the pegasi scouts drew weapons. Twilight’s eyes suddenly widened as she realized her mentor, her second mother, her beloved Princess Celestia was standing in the middle of the throne room, rapidly stroking a large stallion phallus that seemed to be attached to her.

All these thoughts left her mind as a tidal wave of thick, musky spunk crashed into her face with impressive speed, knocking the young alicorn onto her rump.

Coughing and sputtering, Twilight did her best to wipe whatever had hit her from her eyes and muzzle, as she climbed back to her hooves, she could hear Pinkie’s giggling mixed in with confused shouting and the clanking of armored ponies. Finally clearing enough of the thick, smelly fluid from her eyes, Twilight looked around and her jaw fell.

The palace throne room was an absolute mess. Bits of glass were strewn about the marble, and in one spot the marble had a sizable, strangely Celestia-shaped indent in it. Celestia herself now lain collapsed next to a bloated looking Luna, inside what Twilight recognized was some sort of highly-complex spell circle.

On the other end of the room countless unconscious mares and stallions, some of them still sporting their golden palace armor, formed fuzzy piles splayed out across the floor and now-ruined throne carpet. At least one intertwined and sleeping pair consisting of a bat pony and pegasus hung from a banister above the throne’s dias. A partially destroyed pillar (thankfully only decorative in nature) continued to shed bits of marble, sprinkling gently onto a pair of thoroughly satisfied looking and unconscious earth pony stallions.

Having quickly taken everything in, Twilight’s thoughts turned inward, she began leafing through memories of her studies until she suddenly remembered having read a book called, “Promiscuous Princess Parties: A study of Ancient Ceremonies, Population, Growth, and Sexual Spellcasting.” well, now she recognized what the spell circle was for...

Twilight suddenly became acutely aware of just what the warm fluid was dripping from her fur. Blushing like an overheated stove, Twilight slammed a hoof into the ground so hard it cracked the marble beneath it. All Twilight’s fatigue and frustration from the day came to a boiling point as she screamed, “THIS DAY CAN GO FUCK ITSELF!”

Twilight’s horn flashed, activating the return rune the unicorn guards had set back in ponyville. Twilight, her friends, and all the guards that had burst into the throne room vanished in a sudden *pop* of inward rushing air.

Celestia lifted her head from the ground as she thought she heard screaming and a loud popping sound, her mane swaying slightly from the rapidly displaced air. Shrugging, her overstimulated mind simply thought, must have been the wind. She placed a large wing protectively over her sister and laid her head over Luna's. Then all was darkness as she faded into a deep and happy slumber.

Outside the shattered palace windows and far up into the bright sky, the sun could be seen shimmering a gentle purple for several minutes before it was suddenly and violently ripped from its place, bringing about the shortest day-to-night transition Equestria had ever witnessed. If one listened closely at that very moment they would swear they could hear a pony screaming threats of hellfire into the night sky.

Author's Note

Well, there we have it... It sure was something. Maybe I'll write more in the future... I dunno.