Author's Note

This story contains fictional depiction of erotic parent/child and/or sibling incest. This is intended as a fantasy. Fiction is a safe space. In real life, the author does not consider consent possible in these relationships and does not support or condone them.

A Good Seed

Pre-dawn light fell across the bodies of the sisters in their secret tower bedroom. The twilight hours had become their private time together, and most of their subjects would have been shocked by how they used it. The two of them had grown much closer in the months since Starlight’s visit. Much, much closer. They had begun spending the morning and evening hours together, making fruit pancakes, sniffing lavender, and talking about the years they had been apart. They had realized they had something in common that no other living pony did — the experience of living for centuries. It was this commonality that lead them to another discovery: the Westermarck effect had a sell-by date, and theirs was long past.

“Harder, sister!” Luna, on her back with her legs in the air, bucked her slim indigo hips against Celestia’s face.

“Hold still!” said Celestia. “I can’t suck on your clit if you keep moving it!” She pushed her hooves against Luna’s trim belly, trying to make her stay in place.

“Let Us help you,” said Luna, wrapping her magic around the back of her sister’s head and jamming her nose into her pussy.

“Mgh mggger!” said Celestia. Her sister’s sex smelled heavy and pungent, like a tropical fruit. She twisted her neck until her lips were over Luna’s tiny, hot little clit, mashing her nose painfully against Luna’s pubic bone in the process.

“You are most welcome, sister!” Luna jerked her hips up into the air, grinding against her sister’s face. Her breath grew hot and ragged. Her long, slim thighs trembled against Celestia’s cheeks. The magic holding her head flickered and frizzled. Luna wailed. Celestia groaned delightedly into her sister’s pussy — as Luna’s climax filled her body with pleasure, so it filled Celestia’s heart with joy.

Later, when passions had cooled, they still lay in bed together. Celestia nuzzled her dozing younger sister’s cheek and wrapped her wing around her. She had missed sex more than she'd realized. She missed a stallion's body, still, and she missed having a foal in her belly even more. But that was not to say that what she'd discovered with her sister was not wonderful. Her sister was vary passionate. And sweet. And cunning. And subtle. Which reminded her of something she needed to deal with right away.

Celestia sighed, and pushed herself up to look down at Luna. “I was going over your proposal for the Night Guard budget,” she said, “and I had a few questions.”

“Please, sister, is now really the time?” said Luna, batting her eyelashes sleepily. “Why waste this precious hour discussing matters of state?”

Celestia rubbed her muzzle against her sister’s. “It’s about those forty-thousand-bit toilet seat covers we discussed.”

Luna squirmed up her sister’s larger barrel. “Our thestrals’ bottoms are so sensitive, yes. They deserve only the best.”

Celestia sighed. “Luna. My beloved. We agreed you could have one hundred and twenty of them. Four-point-eight million bits is more than sufficient to keep your Shadowbolts at an adequate level of readiness.”

Luna laughed. “Shadowbolts? Surely, sister, you are aware that there are no such things as Shadowbolts”

Celestia clenched her teeth. “But if they did exist, four-point-eight million bits would be plenty.”

Luna shrugged. “As long as we are speaking hypothetically, then yes, that seems like a reasonable budget.”

“Then why,” said Celesta, “did last year’s budget contain a requisition for two hundred and twenty-five toilet seats?”

Luna smiled one of her smiles. Young Luna had had a number of very distinctive smiles — the ‘holier than thou’ smile, the ‘Starswirl likes me better than you’ smile, the ‘I’m smiling so politely that it somehow becomes rude’ smile, and of course the ‘I’m about to usher in eternal night’ smile. Mature Luna had added several more, including the ‘I’m about to talk you into something that will make you ashamed of yourself for the rest of your very long life’ smile. Guess which smile this was. “Oh, We were wondering when you’d notice that. We wanted it to be a surprise,” purred Luna.

Celestia’s eyes narrowed. “You wanted embezzlement to be a surprise.”

“We guarantee you are going to love this,” said Luna, clapping her hooves. “We will clear our schedule for the coming night. Meet Us in the sub-sub-sub-sub-basement after moonrise.”

✭☆✭☆✭☆✭

Celestia did not love the surprise. She did not love it at all.

They had walked down through two levels of storage, past the offices of the EUP Corps of Engineers Special Projects Division, past the kraken tank, and down to a level of the palace that Celestia knew for a fact hadn’t been used since before she was born. The vast columned vault had been cleaned, the marble polished until it gleamed. Ponies in lab coats moved back and forth purposefully across the chamber, talking with one another, looking at clipboards, or pushing racks of potions. In the center of the vault was a pedestal with the letters ‘P.R.E.’ boldly embossed on a steel plate.

“Principality Research into Eugenics,” said Celestia, trying to remain calm.

“Yes.” said Luna, smiling innocently.

“PRE,” said Celestia.

Luna nodded. “We thought of it ourselves. Do you like it?”

“Pre,” said Celestia, eyes narrow with rage.

Luna snorted and covered her mouth with her hoof.

Celestia put her mouth close to her sister’s ear and hissed, “Please tell me that you did not waste over four million taxpayer bits on a dirty joke.”

“Oh, no, sister! This is so much more than just a dirty joke. Ah! Here is our head researcher now! Good Seed! Please report. Are the operations of PRE flowing smoothly?”

“They are!” said Good Seed, a round little gray earth pony stallion in a lab coat with small rectangular reading glasses perched on the end of his snout. “My staff is up at all hours making new discoveries!”

“Your staff is hard at work, then?” said Luna.

“Yes! Very hard! My staff never tires!” said Good Seed.

Celestia glanced at his haunch, wondering what his cutie mark was under that coat. A sprouting seed, she hoped. It could be something much worse.

“Would you care to show Our sister how your staff functions?” said Luna.

“Yes! I’m proud of my staff! Follow me!”

Celestia fell in next to her Luna as Good Seed lead them down one of the side corridors. “There is no call to be vulgar,” she whispered to Luna.

“We remember telling you much the same thing when We were younger. You never listened.”

“I was a teenager then. I’ve matured. What’s your excuse?’

Luna smiled coyly and batted her eyelashes up at her older sister. “We went mad, and were exiled to the moon.”

Celestia cringed, a cold fist of guilt clutching her heart. “You know I had no choice.”

“No. You did not. You did the right thing, sister.” Luna touched Celestia’s shoulder consolingly. The touch tingled with shameful pleasure.

“Anyhow, you were always telling Us,” continued Luna, “that We would be more popular if We were more interested in what ponies like to do at night. It turns out you were right.”

Celestia was distracted from that especially painful memory by the large, two-story room Good Seed had led them into. Against the far wall, taking up about a third of the room, was a vast difference engine, grinding and clanking as ponies fed punch cards into it. On a catwalk halfway up the wall, groups of ponies were going over long streams of tape that poured from slots on the machine. The rest of the room was full of ponies working at cubicles. Rolls of tape would be brought down from the gantry, and the cubicle ponies would look at them and mark punch cards, which would then be collected to be fed back into the difference engine. As the princesses were watching, a pony came through another door with a cart full of paperwork. This was handed out in stacks to the cubicle ponies, who began copying the contents onto punch cards.

“What are they doing?” said Celestia, her voice soft with awe.

“They are sequencing the equine genome,” said Good Seed proudly.

Oh bugger her with a fishing pole, Luna was actually doing something useful with her stolen taxpayer bits.

They spent several hours touring the labs, looking at the research division and the department of genealogical record reconciliation. A great deal of work was being done in understanding the genetic relationship between the four tribes, and it was becoming very clear that the four were really one people, different only in superficial features and the type of magic they used. Everything seemed perfectly above board, and Celestia was puzzled why Luna hadn’t simply gone through the usual channels for science funding if she was so passionate about this.

Then they got to the final section of the lab. A section locked behind three adamantium bulkheads. At each bulkhead, Luna and Good Seed had a brief, whispered conversation about whether Celestia really needed to see this. Celestia was prepared for misshapen horrors of genetic engineering, so she was surprised when the final door opened to reveal a one-way mirror looking out on a pleasantly appointed windowless bedroom. Two youngish mares were sprawled on the bed, reading magazines. Celestia was both relieved and bewildered.

“What… what is this?” said Celestia.

“Watch,” said Luna.

Good Seed leaned over to a megaphone set in the wall. “Subjects Loving Chalice and Fertile Valley, you may begin the test.”

“Finally,” said the mare with a pastoral landscape for a cutie mark, leaning over to pick up a small vial from the nightstand. Celestia had first taken her to merely be extremely fat but now realized that she was pregnant. The other mare — with a fancy cup cutie mark — sat up and bounced eagerly on the bed. Fertile Valley drank from the vial and soon began cringing as though she were in sudden pain. Celestia watched in shock as Fertile Valley’s lower abdomen began to change — the clit grew rapidly, flopping out from her body into a dark, flaccid hose. Her pussy lips stretched around it, forming sort of a sheath around the base, and she grew… balls? Faust knew where those came from. They just sort of… swelled up.

“Are you doing all right, Fertile Valley?” said Good Seed through the megaphone.

Fertile Valley gave the one-way mirror a hooves-up gesture. “I’m fine. Great, actually. I am highly aroused and no longer experiencing any pain,” she said, grinning from ear to ear.

“Very good. Please begin sexual relations,” said Good Seed.

Loving Chalice squealed, wiggled across the bed on her belly, and nosed Fertile Valley’s hose, which quickly sprang up into a fat cock with a massive flare. Too excited to bother with foreplay, she went directly to trying to get Valley’s cock into her mouth. Drool dripped from the edge of the cock’s flare, spotting the bed sheets. Celestia began to feel moist.

Good Seed began to speak again. “We’ve begun quietly reintroducing pregnant test subjects into society, posing as successful participants in more conventional fertility treatments. We’re planning on a phased roll-out beginning in…”

“Yes, yes, I’ll read the white paper later,” said Celestia, waving a hoof. Her eyes were fixed on the couple in the testing room. Chalice had worked Valley’s cock into her mouth and was bobbing her head on the monster. It was so big and so deep in her throat that Celestia could actually see the head moving beneath her skin. She needed Luna alone, very badly, right now. She glanced sideways at her sister, who smiled an especially wicked smile. Celestia tucked her thighs together and clenched her massive buttocks, hoping she wasn’t dripping on the floor.

Good Seed wasn’t paying attention, anyway. He cleared his throat. “The subjects are reminded that this is a fertility treatment, and are advised to proceed to penile-vaginal intercourse,” he said, with weary irritation.

“You make it… OH! Oh, yes, deeper, honey. You make it sound so romantic,” said Valley. Chalice made a soft gagging noise.

“Please, subjects. We don’t want a repeat of last time. We’re not spending over fifty thousand EQB a shot to have you two give each other porn facials.”

Valley began to giggle uncontrollably. Chalice slid off of Valley’s dick, lips dripping goo, and began cackling as soon as her mouth was free.

Celestia watched in fascination as Chalice, still giggling, squatted over her lover. Valley guided her shaft towards Chalice’s pussy, and both mares’ giggles turned into ecstatic moans as Chalice lowered herself onto Valley. The muscles in Chalice’s thighs bunched and stretched as she bobbed. Ripples ran through her juicy young body as she impaled herself on her lover’s cock over and over.

“I love you!” screamed Valley, gripping Chalice by the hips, looking up at her with pure passion.

“I love you and I need you to put a foal in me!” screamed Chalice.

Celestia bit her lower lip. She couldn’t take any more of this. She turned and fled, tears coursing down her cheeks.