It was the night of the Nightmare Night Masquerade. The moon had been raised and the royal sisters had each performed the transformation spell on themselves to appear as ordinary unicorns for the night. Celestia's coat was now a pale grey and her mane was a dull pink, laying limp upon her shoulders, same as her tail behind her. Her wings were notably absent as well. They each had wide black Xs painted over their cutie marks, as was customary for the location they were headed to.

The masks they were wearing did not make them stand out very much. As it was Nightmare Night after all, and many ponies were out and about in varying degrees of costume. Luna's mask was eerily similar to the blue helm of Nightmare Moon. Celestia's was mostly white, with a flowery plume and a paper-mâché crown resembling the one she normally wore. It even came with a mâché horn that fitted snugly around her real horn.

"Don't you think that this will give us away?" Celestia asked.

"Lots of ponies dress as their heroes on this most wonderful of nights." Luna said, walking astride her. It was a bit strange being the same height as her now that Tia was significantly shorter in this form. "Nopony would ever suspect a princess of attending... this. Certainly not dressed as themselves. Hiding in plain sight. It's the perfect plan." Luna said.

"I-" Celestia hesitated for a moment as they made their way through the streets of Canterlot. She'd seen all of these streets at one time or another. But it was strange to be traversing them now without a cadre of guards along with her. With her magic as her ally, she was never defenseless. Yet she felt strangely naked without them. Despite the conservative dress she was wearing. She was about to question Luna, before she remembered the important lesson she had taught her earlier about faith. "I trust you."

"It's just up ahead." Luna said.

"How did you even find this place?" Tia asked.

"The night guard had been investigating rumors surrounding this place for some time. When they finally found it, they brought it to our attention. When the full nature of the place had been revealed, we sought to investigate it... personally. What I found was..." Luna trailed off. "I made sure that the investigating team forgot about this place."

"I don't understand." Celestia said.

"Don't worry, my dear sister. By the end of the night, you will. You will understand why these places must be." Luna turned down one more alley. Ahead was a lone pony wearing a simple, white mask and tailored suit. "Okay," Luna whispered, "now whatever he says, do not say anything back! Reply only by slapping him across the cheek."

"What!?"

"It's the password. Say nothing. Only slap him, and he will let us in."

The two mares, short, masked unicorns, walked up to the door.

"Lovely weather this evening. Don't you think?" He said to the pair. Celestia cut a dubious glance at Luna who all but kicked her to stick to the plan. Without another thought, Celestia whipped her hoof across the stallion's face, slapping him. Not hard, but enough to make a sound. Luna could see the faintest hint of a grin at the corner of his lips as he stepped back and opened the door for them, nodding his head ever so slightly as he did. They stepped inside, into the well-lit foyer as the door closed behind them.

"He must get tired of that," Tia said.

"Oh, I wouldn't say so," Luna replied.

"Clothing check," the mare behind the front desk said, she too, also wearing a mask. They each shuffled off their simple coverings, leaving only their masks on. Through a pair of grand doors, they walked into the main hall, a room much larger than the exterior of the building belied.

The center of the room was a large, checker tile floor of marble and ebony squares. Around the perimeter was lush, red carpet flowing into numerous alcoves with massive sofas. In the back of the room were two sets of grand staircases on either side of the room leading upwards in a wide curves to the second floor. The stairs were of a deep, rich mahogany and the banisters were adorned with elegant carvings. Everywhere, the walls were ensconced with massive works of art. Historical ponies depicted in various lewd acts. Everypony from Princess Platinum to Starswirl the Bearded.

Everywhere there were dozens of masked ponies, stallions and mares alike. Some were paired up on the sofas and cushioned platforms around the edge of the room in all manner of sexual states. Many in the crowd in the middle of the room looked toward the newcomers, eyeing them up and down. What little whispered conversation there was, trailed off until only the wet noises of sex could be heard.

"Dibs!" A lone stallion's voice called out from the crowd. The remark was met with a murmur of chuckles from others. Celestia, for her part, was still somewhat in shock at the entire scene. Luna had tried her best to prepare her for what she would witness. But the reality of it was something she could never have truly expected.

"Dibs?" She asked.

"It seems you already have a fan." Luna whispered back. They walked further into the room. Luna noticed her sister looking at all of the paintings on the walls. "Do you like the art? The contributors clearly have a vivid imagination." She walked over to a portrait in the corner. "This one is my favorite," she jested in a lighthearted tone as she motioned to the massive canvas. Celestia looked up at the image. It was a depiction of Princess Luna, as Nightmare Moon in a clearly dominant role with a comically-large strap-on, fucking Princess Celestia from behind, surrounded by a ring of Royal Guard ponies masturbating furiously. Celestia's flowing mane and white coat were streaked with what was most likely not mayonnaise.

Part of Celestia felt mortified that such graphic imagery of her existed. She wanted to rush out and gather up a full platoon of the Royal Guard to march on this place and burn it to the ground. But another part of her, a big part, felt, dare she say, flattered? Yes, it was refreshing to believe that indeed there were ponies out there who thought of her in a sexual way and not just as some untouchable divinity. But if her past experience was anything to go by, if she were to proposition the creator of this work, she was unsure how they would even receive the notion.

"Good evening ladies. May I offer you a drink?" a stallion said behind them, holding a tray of glasses with wine. He was wearing a plain, white mask like the pony at the front door and the mare at the front counter. His only other accouter was a simple collar and bow tie as a waiting staff symbol.

"Thank you, I am just parched!" Luna said, taking a glass. Celestia shook her head no and he headed on his way.

"So how does this work? There's no charge at the door and free libations. Who pays for all of this?" Celestia asked.

"As I understand it, the proprietor is phenomenally wealthy and a bit of a recluse most of the year. For them, the prospect of hosting the biggest orgy in Equestria is motivation enough for the expense," Luna said.

"The proprietor?"

"Take a look around. They're out here somewhere." She motioned to the crowd of masked ponies.

"But to have enough money for... all of this, that can't be a very long list of ponies, even for Canterlot." Celestia said. Luna looked around them to make sure that nopony was listening.

"When this place was first discovered, they did a bit of digging. But all of their investigations turned up dead ends of pseudonyms and false accounts. If you go far enough, the pony who technically owns this building..." Luna looked around once more, "is you. That was when it was brought to my attention. I assured them that they were mistaken, buried the investigation and quelled any rumors before they got started." She finished her wine and placed the empty glass on the tray of another passing waiter. "So stop asking so many questions before you get us both in trouble. And go; Enjoy yourself." She grinned behind her mask and wandered off to mingle, flagging her tail at anypony within striking distance.

Celestia distance herself from the lascivious portrait of her. She scanned the room of ponies, hoping a waiter would pass by again. She was starting to feel like she could really use some wine.

"Celestia?" She heard a stallion say to her nearby. She turned in surprise to the voice. He had yellow fur and an orange tail. He was a bit on the tall side, even for a stallion. But he was very lanky. His mask was part of a galea helmet with a red plume on top, reminiscent of ancient Pegasopolis. But even behind the mask, she could tell he had a very strong jaw line. His Cutie Mark, like everypony's, was blacked out with fur paint. "Your mask. With the crown. It's Celestia, right? That's pretty hot!" he said.

"My mask, yes." Tia answered nervously.

"Almost as hot as your flank," he continued, closing the distance between them and putting his hoof on her hips. "My, uh- I'm used to mares with a bit more junk in the trunk, but yours!"

Celestia tensed up. She hadn't had hooves on her in a familiar way like this in some time. Even longer since she didn't feel like she was in control of a situation. Her first reaction was defensive, to call her guards on this uncivilized brute. For a random stallion to just waltz up and begin feeling up her flank was a completely alien experience for her.

And exciting.

She shuffled her hooves a bit, having suppressed the instinct to run. This was what she came here for after all. Luna had been quite clear about the nature of the event, and she should expect this. But for it to actually be happening... He moved around behind her, taking in her body from all angles as he continued to grope her aggressively. He took her tail with a free hoof and gave it a firm pull upwards.

"Oh, and that ass!" He knelt and gave her hind an experimental lick. Celestia couldn't really see what he was doing, and the wet contact came as a shock. He could feel her cheeks clench in his hoof and her marehood reflexively winked at him. He grinned and kissed her clit, giving it a little suck.

"EEP!" Celestia squealed. Not loudly, but it was of a high enough pitch to confuse nearby bats outside.

"You like that huh?" He stood up and pulled at her elbow, and pressed his other hoof into her back causing her to buckle forward, her other hoof kept her face from pressing into the floor with her ass up in the air. He needn't hold her tail up any longer. Her own base desires had taken control of her body. He didn't hold her down with his hoof on her back, rather only pushed her into position and returned to her exposed plot. She felt him put his hooves on either cheek, gripping them and kneading them like an expert bread baker before spreading them apart to an obscene degree.

Her pussy parted slightly at the tension. Cool air caressed her inner folds in a way she hadn't thought possible before. It was replaced with the sensation of hot, moist air from his nostrils in ragged breaths before he dove in, licking with wild abandon. She pawed fruitlessly at the floor as she felt his tongue running up and down her marehood, probing her deeply when he reached her honey pot. He was diligent in leaving no part of her unattended, kissing and sucking her clit with each wink she gave. She could feel the tension in her tummy building, a knotting pulling tighter and tighter, begging to snap to release. Just a bit more-

The stallion abandoned his ministrations at the last moment, leaving her aching loins in the lurch. She lifted herself to her elbows to turn and complain, but just as she did, she felt the weight of him on her haunches as he mounted her in a practiced motion. His shaft pierced her well-lubricated entrance in a smooth penetration, filling her to the hilt!

Celestia's eyes rolled back as her orgasm rolled through her, a thundering storm of pleasure rushing through her every nerve after a far-too-long drought. Her back arched and her head whipped back and throaty moan bellowed out.

"OOOhhhhHH!"

Luna looked over at the mare being rutted by the yellow stallion as she walked by. A knowing grin crept across her face. She was heading upstairs to one of the many rooms to use that had a bit more utility. With her was a small entourage of stallions and mares alike. Without a word, she motioned to one of them to attend to the mare being rutted nearby.

The masked stallion had white fur and a two-tone blue mane. He nodded in understanding and finished the cocktail corn dog he had been snacking on and discarded the toothpick. Celestia's eyes had barely come back into focus when the new stallion took her chin in his hoof and lifted it as he positioned himself over her. She caught sight of his blue fetlocks on her shoulders out of the corner of her eye. Her eyes then crossed as his throbbing erection came to bear against the tip of her snout. Her mask was but a thin barrier, but left her mouth conveniently available. It was clear what it was he intended for her to do.

Many years ago, when she last had a stallion bold enough to 'allow' himself to service her needs, he had not even contemplated the prospect of asking her to felate him. But now the prospect was upon her. Expected even. She opened her mouth hesitantly, mentally preparing herself. Her preparations were cut short as the yellow stallion rutting her from behind gave her hips a particularly forceful push with his own, shoving her forward onto the other cock. The white stallion moved the moment he felt the wetness of her mouth on him, humping deeper into her mouth.

In a time gone by, Celestia would dare say she was quite good at the craft of pleasuring a stallion with her mouth. Indeed, she had a fantastic control of her gag reflexes. But that was ages ago, she realized as she felt the stallion trying to force more of his length into her mouth. She tried to remember her technique. It was just like riding a bicycle, she reasoned. Although it was like trying to ride it with your mouth. And it was a penis. She realized that it was not a very good analogy. Clearly she was not thinking straight. Likely due to her presently getting her brains fucked out. Celestia took a quick inhale of air before she was made to swallow more of his length, pushing deeper into her throat.

"Your husband must be really lucky to have a mare that can suck dick as good as you!" he said, pulling her mane a bit toward him. Celestia was a bit taken aback at the implication that she was a married mare in a place like this. "My wife tries, but she doesn't have your talent!"

"At least your wife tries," the yellow stallion rutting her remarked, huffing between thrusts. "After two foals, my wife barely even touches me." His movements became more and more frantic, she could feel his tip flaring inside her. She feared that he would finish inside her. In spite of everything, she had neglected to do any magical contraceptive preparation. "I guess that's what I get for-" he pulled back a final time, popping free of her pussy, "not pulling out," he grunted, spraying cum up onto her back. The last couple of spurts dribbling onto her flank as he slapped her ass with his softening cock one last time.

"UNGH, you sure have a pretty mask," the white stallion said. "Would be a shame to glaze it so early in the evening." She felt him beginning to swell. "So I guess I won't." He pulled back just enough to leave the head of his dick inside her mouth when she felt the first spurt erupting inside. Her first taste of semen in a longer time than she would care to remember. But she hadn't even time to taste it before the second spurt filled the rest of her mouth. She quickly swallowed as much as she could. But she couldn't prevent a generous volume from dribbling from her lips, down her chin and onto the floor.

"I was actually just about to head upstairs. That other mare is putting together some kind of group action and I don't want to miss out on that," the white stallion said. "You two should check it out." The yellow stallion had recovered, Celestia got to her hooves and they each followed him upstairs.

On the second floor they passed by a series of doors close together, one of them opened and a blue stallion, with a darker blue mane stumbled out, with his dick flopping freely with fresh cum dripping. He shuffled away from the group, off in the direction they were headed.

"Wow! I'll have what he's having," the white stallion said. He peered into the room that the blue stallion had just left. It was small, and empty, save for a modest hole in the wall. "A glory hole!? Radical!" He looked at the other two. "You go on ahead. I'll be there later. If there's more dick sucking to be had, I'm going to get my fill!" he said, rethinking his words. "Or, rather, give my fill." He grinned and closed the door behind him. Celestia and the yellow stallion proceeded down the hallway.

Celestia kept on walking, but the yellow stallion waited back for a moment, looking at the door that clearly led to the adjacent room on the other side of the wall with the hole. He was curious to see what kind of mare would want to spend the entire evening sucking dick when his own wife found the act so revolting. Opening the door, he could see the mare already busy at tending to the new phallus poking through the wall. She had lavender fur and a violet mane with a streak of pink running through it. Her mask was sticky with the previous stallions' cum, plastering her nerdy bangs to it. It wasn't what he expected. But then, he didn't know what he was expecting. He closed the door and left. She never even glanced at him. He caught up with Celestia at the end of the hallway who was standing with a couple of other ponies.

"... and after my son joined the service and my daughter moved to Ponyville, I figured it would be a second renaissance for our marriage," the blue stallion was saying. "But after raising two foals, I guess we just kinda lost that spark."

"You have foals too?" the yellow stallion asked.

"Yeah. I mean, not anymore. They're grown up now," he answered.

"We just had two foals. Twins."

"It just kills the intimacy doesn't it? I mean, you still love her but you're both so busy, and always tired,"

"The two AM feedings. Changing diapers."

"You just never have the time. And then when you do-"

"All you want to do is sleep."

"I know, Right!? "

Celestia listened to the two married stallions, fathers even, commiserate. One that had just rutted her a few moments earlier. And the other having just received fellatio through a hole in a wall. She was still finding it difficult to believe that such otherwise responsible ponies would be here doing... this. The Solar Princess of Equestria wiped a bit of random stallion semen from her chin and pondered her own hypocrisy.

The door opened and another stallion stepped through. He had white fur like the other one, and a similar blue mane. But even through the mask, he was clearly older. The confidence in his step made him seem more distinguished, as did the blue mustache peaking out just below the bottom of his mask.

"Are you... here for the orgy?" he asked in a matter-of-fact tone, with a distinct Trottingham accent.

"Yes!" the two stallions answered in unison. He turned and looked at Celestia.

"Madam?" he asked. The group looked at her.

"I- I suppose I am as well," she said. He nodded and took a step back, throwing open the door. The group walked inside to quite a sight.

Celestia beheld a large circular bed in the center of the room, covered in red, satin sheets and various stains from pony-knows-what. There were stallions and mares all about writhing in a sort of formless mass, moving from partner to partner, various moans of pleasure escaping the pile. High pitched squeals of mare in ecstasy and the grunts of stallion climax as white globs would arc through the air landing on whomever was unfortunate enough to be caught beneath.

The stallions accompanying Celestia had already entered the fray, mounting each the nearest mares and pushing them side by side around the room. "Six legged race!" a random pony called out, to a smattering of laughter from the group.

Celestia's view of the middle of the bed was obscured by a trio of stallions standing shoulder to shoulder with their backs to her. In front of them was a mare standing on her hind legs, holding on to them for support as she hopped up and down. Celestia made her way around the room, trying to see into the tangle of bodies and legs. The mare in the middle was sucking the center stallion off with the other two stallions' dicks in either hoof. Beneath her was another, fucking her marehood from the bottom, and behind her was yet another, penetrating her anus. The mare on her hind legs was squatting on her horn from above. Other ponies not directly involved were maturbating or fucking eachother as they waited their turn with the mare in the middle.

In the center of the action, Celestia saw the pony she knew to be her sister. She looked up from the mass of sex at Celestia, letting the cock in her mouth slip free as she came up for air before calling out to her.

"JOIN US!"