(I’ve been working on this on and off for weeks now because it kept crashing my art program, since it was so big, but it’s finally done. there will probably be a part two with the aftermath)
 
Story -(i guess)-
 
Pinkie Pie let out a loud gasp, mouth hanging wide open as she stared at the floating, glowing Discord.
 
“Girls!” Twilight shouted, lighting up her horn with some difficulty, “We’re… we’re fillies again!? Where’s our cutie marks?!” She looked up, eyes finally resting on Discord. “Discord..,” Twilight growled in annoyance.
 
“Oh, Twilight,” Fluttershy soothed, letting out a small chuckle, “I’m sure Discord will change us back once he’s had his fun.”
 
“FUN? Is turning us into cutie mark-less fillies supposed to be FUN?!” Twilight’s face was turning red with anger, steam coming out of her ears.
 
Fluttershy shared a knowing glance with Discord. “I’m sure you’ll have fun, Twilight.”
 
“Well, I think this is cool!” squeaked Rainbow Dash, voice just as it was when she was a foal, “I wanna know if I can still do a Sonic Rainboom with these little wings!” Rainbow shot into the air, doing flips with ease, and finally landed back on the ground.
 
Twilight turned to Rarity, who was gazing at her blank flank. “You’re not just gonna be okay with this, are you?” Twilight was practically pleading at this point.
 
“No, of course not, darling… although I am getting quite inspired to do a line of fillycore clothing.. ooh! I could do little bows here, maybe even..” Twilight turned away as Rarity prattled off about fashion, turning to see Pinkie with the same expression as she had several minutes ago. She poked the pink filly with a hoof.
 
Pinkies whole body shivered and she snapped into action. “Oh my gosh, this is amazing! I’m so tiiiinyyyyy!” Her voice raised several octaves on that last word, causing Twilight’s ears to ring. She sighed exasperatedly and turned to Applejack, who was looking away with contempt, and muttering under her breath.
 
“How am Ah meant to do all of my chores with this little body. Why, Ah’m as small as Apple Bloom, there’s no way Ah can,,” again, Twilight turned away from her muttering friend.
 
“DISCORD!” she shouted, flying into the air on her little wings, glad she had remained an alicorn regardless of the age transformation.
 
“Oh, whatever is the problem, my dear Twilight?” Discord asked smugly, swooping around to nuzzle Fluttershy. “Don’t you think this is the perfect opportunity to do some research?”
 
Twilight’s pupils expanded and her eyes sparkled. “Oh my goodness, I can learn so much about how young bodies work and write it all down with my full grown mare mind!”
 
Discord guffawed loudly, eyes glinting with mirth. “Oh, you’ll have plenty an opportunity to find out how that little body works today, Twilight.”
 
Twilight paused in her ruminating. There was something about that tone of voice she didn’t like. “What do you mean by that, Discord?”
 
Fluttershy approached her and whispered in her ear.
 
“What?? No! Absolutely not, never, no, not in a million years I will never,,,” Fluttershy booped her nose to hush her, and whispered again in her ear. Everypony looked on intently at the two engaging in hushed discussion, and then they all gathered in a huddle to discuss.
 
Twilight let out a huge sigh. “Ugh, fine. As long as everypony agrees, I guess this is a good opportunity to learn some stuff.” Twilight pouted.
 
“Oh, yay everypony. Discord and I are so excited to share this time with you.” Fluttershy smiled.
 
(Part two eventually, with the aftermath of their orgy thing)  
“Background from here”:https://www.deviantart.com/breadking/art/Everfree-Forest-Background-1-281364421
 
PART 2: “HERE”:https://derpibooru.org/images/2395229

imported from https://derpibooru.org/images/2392245