Eternals
"Oh, DISCORD!" cooed Fluttershy happily as her big, strong draconequus boyfriend rammed his infinity cock into her vagina. She screamed and cried in pleasure as Discord, gripping her sides, climaxed inside of her, her meager ponut overfilling rapidly with cum. "MORE, MORE!!!" she cried, as Discord grew a second penis that rammed straight up her ass. As it began to pulse and throb, he moved his mouth in to kiss her, practically swallowing her mouth with his own, rubbing his tongue all over. Fluttershy continued to sob and moan in absolute pleasure as Discord increased his tempo, unfurling several dick-like tentacles with minds of their own to wrap all around Fluttershy, covering every sensitive place on her body with pleasurable massage.
Fluttershy couldn't even fathom how happy she was right now. As her body bobbed up and down, her mouth engaged in sloppy, intimate kisses, she continued to tear up and beg for more in her mind - Discord could read it, so that's all she needed. Her pleasure was entirely automated. A mare literally could not be more lucky.
Pinkie and the others always asked why she was in such a good mood all the time. She wanted to tell them, but it also felt exciting to keep such a fun, juicy secret. She would love to see the looks on their faces when they found out that she was not only the most sexually active of the group, but she had the freakiest sex! She couldn't even keep track of how many senses were being bombarded with endorphins right now, and she shrieked and creamed herself in pleasure as Discord released his final loads all over her body. Loads of cum splattered all over her, from all angles, at nearly all intensities. Even as the mighty creature withdrew, breathing heavily due to the exertion, she continued to roll around and sob and squeal in absolute pleasure. For several minutes, she continued to roll around, her tiny vagina squirting as she laughed and giggled, her mind still on a complete high of endorphins.
"You're....welcome..." spoke Discord between labored breaths. He loved Fluttershy so much that he put an insane amount of energy into pleasuring her, having to handle multiple bodies, sex organs, tentacles, and even mindreading at the same time.
It was starting to feel a little boring, though.
"Discord...! DISCORD!" she shrieked randomly, still laughing and crying in pleasure. "Oh, I love you, I love you SO MUCH!" A tiny bit of cum spritzed from her vagina in the excitement.
"I love you too, Fluttershy," replied Discord. His mind began to wander a bit, watching his tiny, cute marefriend roll around in a puddle of his and her own semen. She rolled onto her stomach, her mighty fine ass on display for a few moments before tumbling back on her back, continuing to innocently paddle the air in pleasure. She was starting to calm down just a bit. What could he do, to be less bored?
He could kill her.
Discord blinked. He looked at Fluttershy again, his source of happiness. For thousands of years he had lived, and nopony had ever made him feel like her. Kill her. What did he just think? What the fuck was that? She began to giggle some more, now rubbing her own vagina, whispering his name over and over.
Yeah, it's time for her to feel ungodly pain and die.
In Fluttershy's mind, she was still in paradise. As she softly rubbed her pussy, she imagined Discord and her having a future, a long and storied future, full of family, love, and affection. She began to hum and buck her hips a little, before rolling on to her stomach, horny already again. She began to wave her butt at Discord a bit.
"Mmmm, Discord, how do you like this?" she asked, trying to act as sultry as possible. Discord blinked, staring one more time at the pure, innocent eyes of his lover, and the best ass he had ever seen on a pony.
He grabbed her suddenly by the hoof, yanking her off the ground. The yellow pegasus squeaked in surprise, the sudden jolt frightening her. Before she could ask what was happening, Discord grabbed one of her wings with magic, and tore it effortlessly from her back, shooting a geyser of blood from the hole - this all happened in a matter of about five seconds.
"WH-WHA-AAAAAAAAAAAAAAAAAAAAAAAAAA!!!!!!!!!!!!!!!!!!!!!" shrieked Fluttershy. She instinctively kicked and screamed. "WHAT ARE YOU-"
Discord, with a blank stare, ripped her other wing from her back, dropping her to the ground. Fluttershy shrieked and wailed in pain and confusion, landing on her stomach. Discord watched emotionlessly as she began to slowly crawl away, her cute, fat, juicy ass wobbling back and forth.
"Wait," he spoke quietly.
"DISCORD, WHY, WAIT, PLEASE WAIT, DISCORD, WHY-" blubbered Fluttershy as Discord appeared right behind her and smacked her in the ass, hard. She yelped, and he continued slapping her over and over in the ass.
"PLEASE," she sobbed, barely able to get a word out.
Discord shoved a claw straight up her vagina, breaking the skin around it which was too small to hold his entire fist. Fluttershy nearly blacked out from pain as the mighty draconequus grabbed her clitoris and ripped straight down, tearing it from her body, dragging several other vital organs from her crotch with it. Fluttershy vomited blood. Discord continued to breath slowly and emotionlessly as he threw her to the ground, giving her just a moment without pain as he stared at her, observing her despair. She began to crawl again, pissing all over herself in fear and pain.
"D...DISCORD, P....PLEASE, WHY ARE Y...YOU....." the helpless, innocent pony sobbed, "I...I DON'T WANNA DIE, I...."
Without a reason or prompting, Discord simply walked over to her and wordlessly starting kicking her, bracing himself on a nearby table, slamming his cloven hoof down on her jaw several times. In response, she moaned as loudly as she could, pleading, begging to be saved. Discord picked her up with magic, rotated her to face him, and grabbed the top and bottom of her jaw with his claws and yanked hard in either direction, ripping the bottom of her face off. He then summoned a spear and hurled it through her stomach, pinning her to the wall. She sobbed and cried, making any noise she even could still make as her tongue fell limp out of her gaping mouth. She pissed and shat herself as she began to lose autonomy.
"Oh no," lamented Discord, "I'm getting bored again."
Discord threw another spell at her, causing her to shriek and wail with every ounce of energy she had left - except she found she couldn't stop. An insane, searing, agonizing pain hit every cell in her body, more intense than anything she had ever felt in her life. She thrashed around in torment, unable to process this level of pain. She wished to die, for this all to just end.
"It's never going to end," spoke Discord calmly, reading her mind. "That's a pain spell with attached immortality. I shall now banish you to a dimension of pure agony, where every second that you remain alive, your pain will increase by a factor of ten, with no upper bound. Within seconds of existing there, you will experience more combined pain than all of ponykind has, collectively, in history."
The portal opened next to her. Fluttershy, feeling more abstract horror than she could ever think possible, vocalized and thrashed with every ounce of her being, desperately not wanting to fall in. She managed to belt out a single audible "WHY!?!?!?!?!?!" before falling into the dimension, immediately feeling the pain increase by a factor of ten every second, throwing her head back in pure, uncontrolled, unadultured agony.
"Because I'm bored. Goodbye, my dear," answered Discord, closing the portal - the last thing Fluttershy ever saw before being locked in her own personal hell was the creature she loved, she trusted, she believed her future with waving goodbye after committing the ultimate betrayal.
As the months, years, decades, and centuries passed, Discord would always call upon the portal to view Fluttershy again.
The best part was that he never got bored again.
In a way, Fluttershy had become his eternal.