It was a breezy summer's day in Ponyville, when Princess Twilight Sparkle was dusting her bookshelves. Her loneliness was interrupted, however, by the abrupt entry of Rainbow Dash.
"Rainbow Dash, I've told you time & time again to use the doorbell!" Complained the princess, referring to the elaborate system of pulleys attached to a pull chord by the front door, which would find Spike wherever he was and inflict pain upon him, so that his screams would alert Twilight that she had company.
"Yeah yeah yeah, I punched Spike on the gut on the way in. Anyway, this is SUPER. IMPORTANT."
"What is it? A friendship emergency? Is your butt flowing?"
"What? No, WAAAAAY more important than THAT."
"Then what?"
"Can I use your portal to the hairless monkey world?"
"..."
"Kaythanksbye!" Rainbow shouted as she sped off to the portal room.
Upon entering the room, Rainbow Dash found herself at a loss for what to do, until Pinkie Pie appeared from nowhere.
"Hey Dashie! Watcha doin'?"
"Um, hey Pinkie. I'm trying to activate Twilight's portal here."
"Ohhhh! Are you trying to use it so you can meet your alternate-universe counterpart and have sex with her because your narcissism & ego are to such a degree that you will never be sexually satisfied unless you make yourself orgasm but find yourself bored of masturbating after faking orgasms with Applejack?"
"Yeah, pretty much. Know how to turn this thing on?"
"Sure! Can I watch?"
"What? No!"
"Pleeeaaase?"
"Pinkie, no."
"I'll turn the portal on if you let me watch."
Rainbow Dash sighed.
"Tell you what - If you turn the portal on, I'll take a picture and give it to you."
"Oki-doki-Loki!" Said Pinkie, as she pressed the big red button that read "PORTAL ACTIVATION BUTTON".
Without even saying thank you, Rainbow jumped into the portal.
Emerging from the statue, Rainbow surveyed her surroundings, before her eyes locked on to the graceful, elegant form of her wife, Applejack. Or, at least, her human form.
Rainbow Dash ran to Applejack, grabbing her by the shoulder.
"HetAJhaveyouseenRainbowDasharoundhere?"
"What now, sugarcube? You ARE Rainbow Dash, ain'tcha?"
"Nonono, not ME, I mean the OTHER Rainbow Dash. I'm from the Horsiverse!"
"Well, that explains why you're not wearing exactly the same clothes as you normally do. Every day."
Rainbow Dash stared down at herself to admire her attire. To her surprise she found herself in a white tank top, a green hoodie, these weird denim things that clung to her legs, and some strange form of cotton diaper that read "PROPERTY OF APPLEJACK" on the flank area.
But what intrigued Rainbow Dash most about her strange new body were these sacks of flesh on her chest. She had no idea what they were, but she instantly fell in love with them.
Wanting to experience more of these amazing funbags, Rainbow grabbed Applejack's chest and started fondling.
"H-hey now, just because me & your alty-nert candapart are engaged don't mean this ain't cheating!"
"Okay, okay, where can I find me? I mean, the weird hairless monkey version of me."
After receiving Applejack's text reading "for extra boobs meet me in the music room", the human Rainbow Dash rushed to said music room, arriving in ten seconds flat.
Rainbow Dash stared in awe of the magnificent beauty that stood before her. Meanwhile Rainbow Dash, too, was staring at the magnificent beauty that stood before HER.
"Wanna make out?" Asked Rainbow Dash.
"Oh hell yes," replied Rainbow Dash.
Immediately the two Rainbow Dashes embraced in a frenzy of narcissism, while Applejack's eyes widened, and her genitals moistened.
About a minute later, the Rainbows & Applejack were joined by the unsuspecting party of Sunset Shimmer, Pinkie Pie, Fluttershy, and Rarity.
Fluttershy's jaw dropped at the sight. She found herself unable to look away. Rarity, too, was mesmerized by the display. Pinkie Pie's face erupted into a grin far too wide for anyone following the laws of physics, and Sunset unknowingly slipped her hand down her underwear.
The Rainbows were far too focused on each other to even notice they had company, and Applejack was too engrossed with the sight of her girlfriend's cross-dimensional selfcest to care.
Out of Pinkie Pie's backpack emerged the pony Pinkie, who had not been given human form, as she had not arrived via the portal.
"How come monkey-me gets to watch but pony-me doesn't? Huh? C'mon Dashie! Dashie? Huh. Guess I'll just watch..."
Pinkie Pie watched for a while before becoming bored.
"Hey, human me? Ever wanted to have sex with a horse?"
"Hm... No. But I totally do now!"
Before you could say "party", the Pinkie Pies were engaging in the most disturbing display of bestial lesbianism ever known to man or horse, and it was making the room of lesbians even hornier, especially Sunset, who was herself a horse.
Unable to take it any longer, Sunset reached for her magic book and sent an urgent message to Twilight:
"I need you to cum here. CHS. Music room. NOW."
Having missed the odd spelling choice, Twilight Sparkle rushed to the portal, and to the music room, to find her girlfriend lying on the floor, her clothes torn off her body, spasming in a mixture of pleasure & frustration, engrossed in the lesbian love fest that surrounded her. By this point Rarity & Fluttershy were going at it like rabbits, and the Rainbows were on their 8th round. The Pinkies were experimenting with toys, and Applejack had brought out her Rainbow dildo.
Sunset looked up to her lover, barely able to speak. Two words escaped her mouth.
"Help... Me..."
Twilight's clothes came off faster than Cherilee's top in the strip club she moonlighted in on Sundays.