Zen and the Art of Horizontal Refreshment

For the next half hour, I methodically downed mug after mug of cider. It takes a lot of alcohol to affect an immortal alicorn, after all. I was highly motivated, not only because of...that subject, but also because Luna quickly began to drive me insane. She was bouncing around the room, downing drink after drink from every barrel on the wall and every bottle in the cabinets, a few of which I think were just cleaning products! After drink came with a color commentary of how great it was and how much I was missing out drinking nothing but my simple cider.

I did my best to tune her out, and fortunately, my simple cider eventually had the desired effect. My anxiety faded to a dull hum, I felt myself blush, and I let a stupid smile play across my face.

I sat on my haunches and waited for Luna to notice me again. She finished chugging her latest find and glanced over to me. I could see the blush in her face beneath her coat...no matter how much of a drinker she was before, she was a thousand years out of practice, and was likely feeling the liquor \even more than I was.

She sauntered over to me with exaggerated steps. "So, Tiaaaaaaa~~ What's the big secret?"

Somewhere in the back of my mind I felt myself try to tense up, but there was a mile of fermented apple between that feeling and the rest of me. I grinned even wider and leaned in to answer in a drunkenly loud (but regal!) whisper, "I'll show you." I cracked up into a giggle.

"Show me! Show me!" Luna replied.

"Not here." I haltingly stumbled toward the wooden door to the next room. Luna followed dutifully behind. I opened the door, revealing a modestly appointed bedroom with a gigantic four-poster bed. I stopped short, realizing that I was revealing this wicked chamber to the first pony who would ever remember it. Feeling myself starting to tense, I took a deep breath, letting the worries drain away before jumping into the room and flopping onto the overstuffed mattress.

"Just a bed?" Luna inquired behind me. She listed heavily to one side as she made her way forward. "With the way you were carrying on, I expected some horrible laboratory with half-formed ponies in glass tubes!" She giggled as she staggered against the wall.

I smiled, choosing not to flash back to the grotesque horrors of the biomagical cloning laboratory that had consumed my early efforts. "Of course not! That would require isolating viable phenotypes across a diverse cohort of all three pony subspecies---and it was wrong! I mean, it would be wrong."

Luna was too busy trying to right herself to notice my slip-up, and I was too tipsy to care much anyway. She eventually righted herself back on all fours. "Well, sister, will you show me whatever it is already?"

I'd better not give myself time to hesitate, I thought.

I did my best to seem confident. "Yes, on with the show!"

Alright...here we go.

Before I had a chance to stop myself, I began casting the Forbidden Spell, the Cantrip of Andromorphy that I had shamefully developed in secret in this place all those centuries ago. The dark secret that had powered all Equestrian reproduction for over fifty generations began to take form. I shifted uncomfortably as my nethers began to reconfigure. My delicate marehood gave way, and I could feel a sheath form which was soon populated by a distinctly male member. I braced for the worst part. I grunted at the awkward sensation of two testes plopping into place. I let out a breath I didn't realize I was keeping and relaxed my muscles before looking up at my sister.

"There. Now you know."

Luna just stared at me in uncomfortable silence. Her face scrunched up in confusion. No, no, she's judging me. I'm a freak!

Finally, she spoke. "That's it?" she asked.

I blinked. She didn't seem mad or ashamed, just...annoyed?

"Is that all?" she continued. "Is that seriously it?" She stared at me with exasperated eyes. I was too stunned to respond, so she continued, "You burned a hole through the foundation of Canterlot castle, masked it with magic, layered it with deadly wards, bored a tunnel down into the center of the mountain, and filled it with enough liquor to get the whole Royal Guard fall-down drunk, all because you wanted to grow a dick and fuck mares? Really, sister? Do you know what ponies in my day called it when I did that? 'Thursday!'"

I was at a loss. Luna knew of this spell?

"And after all that build-up?" she continued.

Luna thought this was normal?

"Riding on that lift in silence down to what I assumed was some mutant pony dungeon!" she barked.

Luna had used this spell herself?

"And all the liquor, just to work up the courage to show mares how to grow penises? That's hardly the worst thing in the world. It's not even a bad thing! It's even a bit clever..."

Wait, what did she just say?

"And besides, our ponies are probably used to it by now, so it's hardly worth all this---"

I snapped back to reality. "Wait!"

"What?"

"You think I showed other ponies how to do...this?" I reared up and gesticulated wildly at my stallionhood.

She squinted in thought for a moment. "...yes?"

"Ugh, Luna, NO! I would never teach one of our ponies this repulsive spell! I'd never admit this to anypony!"

"Then, what? What else are you going to do, impregnate every mare in Equestria yourself?"

Oh dear. When she said it out loud, it did seem a bit...crazy. I snapped my eyes to the floor, unable to respond.

"No, Tia, you didn't...."

I bravely studied every twist in the swirling patterns of the granite floor.

"TIA, THERE'S NO WAY!"

I considered trying to teleport more alcohol directly into my bloodstream, or perhaps banishing myself to the moon.

"Tia, look at me."

I froze.

"Look. At. Me."

I slowly raised my head and met her eyes. She was genuinely bewildered.

Luna continued, "do you mean to tell me that you have personally sired every foal to live in the last 1000 years?"

Excuses ran through my head. Griffons did it? Discord did it? Changelings did it? Cadence did it? No good. I let out a long sigh. "Yes."

Luna's expression changed to one of concern. "Tia, that's crazy! The math doesn't even add up! And, wait -- that would mean that you've been impregnating your own foals, grandfoals, grand-grand foals, and on and on, for a millennium!"

"Yes." There was more to it than that, but overall she was right.

"No, that's not something you say 'Yes' to! It's--it's--it's...absurd!"

"But it is true, sister. All sex in Equestria for the last millennium has been with me, personally, in this place."

She fell back onto her haunches, still listing a bit to the side from the alcohol. After a few seconds, her face calmed, and she spoke one word. "Explain."

"Very well..."