Twilight Sparkle cried out in pain as Princess Celestia penetrated her tight little horse asshole with a long, black, ridged magical penis she had casted on herself. It was excruciating, and had she known Celestia was going to fuck her in the ass, she would have never come. However, the fact of the matter was that right now, whether she wanted to or not, she was going to come one way or another.

"OH CELESTIA, I'M GOING TO CUM! AHHHHHH!" Twilight's whole body shook as the co-ruler of Equestria pounded her bleeding asshole over and over She hadn't even used lube, and the purple unicorn's anus was raw from the friction. Nonetheless, Twilight's orgasm took over and she was in ecstasy for a few moments before she crashed back down to reality, the searing pain once again filling her mind. "IT HURTS, PRINCESS CELESTIA! YOU'RE TEARING ME APART!" she screamed.

Princess Celestia just snorted while thrusting her black penis as far as she could inside the pathetic mare. "Shut the fuck up, you little bitch!" she sneered. "Nopony said friendship was easy. In fact, this might just be the hardest lesson I've ever taught you." Celestia cackled at her own joke. She was quite hard though, and Twilight's tight butthole slurping her dick was doing wonders for her. She hadn't felt such a tight hole since she had fucked that farm pony's little sister, Apple Bloom. I guess the smaller, the better, and the only way to go smaller is to go younger. She was aware of her former pupil's shrill cries of agony mixed with perhaps a slight bit of pleasure, but it didn't matter what Twilight wanted now. Celestia was slowly building up to a glorious release, and Twilight was going to take her there whether she liked it or not.

Twilight was sobbing openly now, her back legs twitching every thrust. Her anus spasmed with the pain of a million anal fissures, and as darkness ate at the corners of her vision she wondered if she could slip mercifully into unconsciousness. However, Celestia had no plans of letting that happen. The powerful ruler ripped her cock out of Twilight's ass as she felt the princess's body growing limp under her thrusts, causing the purple pony to screech so loudly that she had to cover her ears. Celestia's horn glowed and she teleported in front of Twilight, forcing the crying princess to meet her eyes.

"You will not deny me my orgasm, Twilight Sparkle." She reached down with a hoof and gave Twilight's ass a hard slap, forcing another scream from her. "Pop quiz, Twilight. How many nerve endings are there in the anus?" she asked.

"I... I don't know! No textbooks ever listed an actual estimate!"

Celestia shook her head in disappointment. "Oh? You're wrong, but let me ask another question. How many nerve endings are in the clitoris? More or less than the anus?"

Twilight fought through the pain clouding her mind. Despite her situation, she couldn't turn down a good pop quiz. They were almost as good as sex. More important though, she noticed that Celestia momentarily stopped pounding her quaking asshole when she asked questions. If I can keep her asking... "Um, I read that it was eight thousand, and I guess more!" she said desperately.

Celestia nodded. "That's correct, Twilight. But why is it that..." Celestia stopped for a moment to position her cock back in front of Twilight's back hole, "... the asshole can be more sensitive than the clitoris!?" she cried with glee. And with that, she slammed her rock hard penis into Twilight so hard that she could almost feel her hardness penetrating her womb. Twilight tried to scream, but no sound came out. Tears leaked from her eyes, and her entire body shook in pain. Her eyes rolled back in her head, and she didn't know if she would wake up ever again as the darkness claimed her.

"I have to thank you, Twilight." The purple princess woke up to the sound of a familiar voice in her ear. Years ago it would have given her comfort and joy, but now it struck fear into her heart. "That was the best orgasm I have ever had," Celestia declared. Twilight opened her eyes but couldn't see through the darkness. The stinging pain in her anus was quickly taking over her thoughts again. She noticed something wet underneath her, and to her horror she was dripping blood all over the stone floor. She had no doubt it was from the pounding she had taken before.

"W-Where am I!?" Twilight shouted. She needed to get out. She needed her friends so she could tell them and somehow, they would make it all okay again. "PRINCESS CELESTIA!"

"Shut up you whining piece of trash," demanded Celestia. "You won't die if that's what you're thinking. In fact, you probably won't want to after you see what I have waiting for you."

"DON'T FUCK WITH ME!" screamed Twilight. "I HAVE THE POWER OF THE HEAVENS AND FRIENDSHIP ON MY SIDE!"

"Cut the bullshit." Celestia yawned, waving a hoof in front of her mouth. "Why don't you open your fucking eyes for once and see what I've prepared just for you?" Her horn lit up and the room was suddenly illuminated.

Twilight looked around the room. It was a big, square room that was mostly empty, save for a few large crates or two. She guessed that it was the royal storeroom, which Celestia had tweaked to fit her own purposes. "What do you want from me?" she whispered.

Celestia's eyes grew red with anger and she threw Twilight to the ground with her magic. "How many times do I have to tell you?" she said menacingly. "I already had the greatest orgasm of my life. I'm giving something back to you." She nodded something beside them in the centre of the room. A cloth was covering something, and Celestia lifted it off to reveal another plain looking crate underneath.

The Princess of Friendship tried to avert her eyes in a last act of defiance. Damn, Celestia is a motherfucker. "I don't want to know what's in there," she declared, though she was unable to stand properly due to the shaking caused by the pain of her multiple anal fissures.

"Oh?" Celestia smiled devilishly. "You will after this!" her horn enveloped Twilight in yellow, levitating her briefly as whatever spell she cast took effect. "Now tell me you don't want it again."

The moment the magic reached her, Twilight knew something was wrong. The pain actually vanished, but something else was coming. Something worse than she could have ever imagined, and far worse than the destruction to her anus. There was a change in herself, and she could tell she wouldn't be able to control whatever it was. When she dropped back to the floor, she felt it. She looked down and screamed. It was a big, black cock just like the one Princess Celestia had when she was fucking her brains out. And worse, it was stiffer than a board. Twilight thrust it in the air wildly, trying to stimulate the growing ache in her dick. Unable to think properly, she dragged it along the ground desperately, but cried out in pain as the stones cut the tip of her penis. "AHHH! I WANT TO CUM SO BAD!" she shouted.

"Twilight, is that you!?" Twilight's ears twitched as she tried to control herself, but to no avail. Somewhere deep in the back of her mind she knew that voice, but right now its only purpose was to guide her to the source of two holes which she could use to satisfy her throbbing penis. She teleported over and into the crate, instantly mounting whatever was inside. With one thrust, she tore through any resistance and pumped her cock in and out.

"TWILIGHT, AHHHHH! PLEASE STOP! IT'S ME, PRINCESS CADA-- AHHHHHHHH I'M DYING!!!"

Author's Note

hi everypony!!! im back once again with another story for all of u! once again i am porkcrastating on my homework to write this but i just love writing so much!! um i dont have much else to say i hope u all enjoy!!! oh and um i have heard many other people say this on videos so let me try if u like the story please be sure to give it one big fat like down below!!! have a beaituful day everypony