Zen and the Art of Horizontal Refreshment

Luna leaned in toward Twilight, a Cheshire grin spread ear to ear. "What is the plan?"

Twilight turned from the edge of the Everfree back toward Ponyville. "Walk with me?"

Luna nodded, and the two set off.

Twilight drew a deep breath, and began. "Well, I've had a theory, and I think what you said earlier confirms it. It's based on your transformation into Nightmare Moon. It came about because of acute psychological stress aligned with your desire for sexual gratification, correct?"

Luna's jaw tightened a little. "A little on-the-nose there, but yes..."

"Sorry," said Twilight, looking down for a moment before scientific excitement got the better of her. "But listen! We just need to do the same thing to Princess Celestia, except inverted!"

Luna simply raised an eyebrow.

"Let me explain. I'm thinking if we bombard the Princess with an amount of sexual imagery, activity, and magic in excess of her intellectual capacity to process it, it should trigger a violent prolonged transformative psychic episode, which we can counteract by harnessing the magic of the Elements of Harmony to exorcise the resulting manifestation of her sexual neurosis, thus culling the repression of her reproductive psychophysiology from her psyche!" Twilight beamed, waiting for an A to be stamped on her metaphorical paper.

Luna simply smirked. "So we throw her into an orgy, get her to turn into Nightmare Celestia, hit her with a rainbow, and pip pip cheerio, problem solved?"

"Well, uhm, when you put it like that--", Twilight started to mumble.

Luna's eyes widened. "Why that's...that's..."

Twilight rapidly cycled through the possibilities of banishment, incarceration, and intra-banishment incarceration in her mind.

"BRILLIANT!" Luna exclaimed!

Twilight breathed a long sigh of relief.

"An elegant plan, exquisite in its simplicity and sublime in its daring! But how?"

"Well, princess, that's sort of the problem I was hoping you could help with. I ran the math, we'd need over 1.21 gigabucks to crack Celestia, and it would need to be spread over hundreds of ponies! There's never been enough sexual energy in all of Equestria for that..."

Luna laughed, a ladylike titter at first before it grew to a deep-throated chortle. She raised a hoof and gestured over herself. "There is now, Twilight Sparkle!"

Twilight's eyes widened and she grinned ecstatically before noticing that the pair had reached her door. "Okay, but there's just one more thing, princess. Where will we find an event with that many ponies where Celestia is guaranteed to be that we can basically ruin by turning it into a massive orgy?"

Luna furrowed her brow. "Hmmmm..."

Twilight opened the door and the duo trotted inside, only to find Spike waiting excitedly. Clutching a scroll in his claw, he ran up to them, exclaiming, "Twilight, it's about time you got home! A letter came from Princess Celestia! We've all been re-invited to the Grand Galloping Gala...I've got the tickets and everything!"

Luna and Twilight simply looked at each other, grinning.