Princess Luna strolled through the halls of the castle, nodding to each guard as she passed. Her eyes finally fixated on her destination, and she magically threw open the doors, marching in. There it was. Laying plainly on the table was the one key to her embarrassment. An image of her as a young filly, taking her first bath. Her marching continued towards it, and she reached a hoof out to grab it, when she was hit by an extremely painful electric jolt.
"What in Celestia's mane!" She exclaimed, withdrawing her hoof with a mild whimper.
"You called?" Celestia emerged from behind another set of doors, flipping her mane over her shoulder as she entered.
"Celly! How dare you take this picture! How'd you find it in the microscopic blackhole only I can navigate in the back of closet underneath the seventeenth shirt but above the illusioned one kept inside a wooden box sculpted by my ex-boyfriend's second cousin?" Her voice rose with each location, while her sister's delight increased as well.
"You foal! You showed it to me on the third day of the first month after mom ate that chocolate cake you wanted!"
"Why!" Luna's moan was accompanied by her slumping on the table, her head clanging against the wood. "Why would you think I didn't have my own weapon!" She magically held up an image of Celestia when she was in her teens, blushing and hiding cake pans behind her back.
"H-how dare you!" Exclaimed "Celly", using her magic to grab the image. She was unable to, however, as Luna had encased it in her own magical shield next to Celestia's on the table.
"Now, I'd suppose you'd like to work this out, correct?" Asked Luna, sitting down on the table with a smirk.
"I suppose," sighed Celestia, twirling her hair. "We are at an impasse, are we not?"
"Then I challenge you to an arm wrestling match!" Luna's voice echoed over-dramatically through the room, and lightning crashed behind her. "Thanks, Nimbus," Luna whispered over her shoulder.
"But Lulu..." Celestia's voice rose into a whine, her eyes pleading.
"Unless you want this image to hit Equestria Daily..." Luna swung the image tantalizingly in front of Celestia's nose before tucking it back on the table.
"Fine! Be back here after you raise the moon, sister."
"Very well, Tia." They glared at each other and left through the same doors they had entered, their hooves pounding against the carefully polished floors and scuffing away the polish and wax as they went back to their chambers.
When the two returned to the table, a small crowd was gathered, and Shining Armor stood with a whistle around his neck in the middle of the two of them.
"Both of you agree to the rules, correct? No magic, wingpower, or otherwise cheating using Five-Hour Energy, Discord, or other energy drinks." The two mares nodded simultaneously, narrowing their eyes at each other. "At my mark, you may begin." The two reached their right front hooves out, flexing them angrily. "3...2...1... Mark!" Declard Shining Armor, a smile on his face. The two mares grabbed hooves, starting lightly as they attempted to push the other's hoof to the table. Slowly, however, you could see them gritting their teeth with effort as their hooves struggled against each other, while Princess Luna attempted to alleviate the stress.
"So... fair sister," she grunted through clenched teeth. "How are you tonight?"
"F-fine," muttered Princess Celestia, clearly the worst off in this struggle. Without warning, the doors burst open, and Twilight Sparkle ran in, turning to her brother.
"What's going on?"
"An arm-wrestling match. We may be here for a while, Twily."
"Oh boy," sighed Twilight, magically pulling up a La-Z boy chair and settling down into it. "Oh boy."