Image imported from derpibooru 
Original Description:
 
Starlight Glimmer and her friend, Trixie (the Great and Powerful) were enjoying a pleasant stroll through the streets of Ponyville on what seemed to be a fairly ordinary spring afternoon. The sun was shining, the birds were chirping, and absolutely nothing of the usual apocalyptic sort had happened in at least three weeks, so it was shaping up to be a good day, all things considered.
 
“It was nice of Princess Celestia to come all the way down to Ponyville just to meet us for an early dinner, don’t you think, Trixie?” Starlight asked her companion as they trotted their way towards the quaint cafe they had agreed to meet.
 
“But of course, who wouldn’t travel far and wide to spend an afternoon with the Great and Powerful Trixie?” The blue mare proclaimed, perhaps a little too loud for public conversation. “And her lovely assistant.” Trixie hastily added with a slight giggle.
 
Starlight couldn’t help but chuckle along with her friend and the due helped themselves to a pair of cozy little seats at a table in front of the cafe they had just arrived at. They chatted idly with one another and politely dismissed the waiter, informing him that they were waiting for a friend before ordering. He smiled and left the two to their conversations.
 
Then an hour passed.
 
“Hey, Trixie, it’s been a while, don’t you think the Princess should be here by now?” Starlight asked, with a slight hint of concern in her voice.
 
“Naaah, she’s probably just been held up by-” Trixie paused, thinking of a plausible reason the Princess could be so late “- important Princess-y stuff!”
 
Starlight mulled it over and decided it best not to worry, Trixie ultimately talking her into ordering despite Starlight’s protests that it would be rude to eat before the Princess arrive. Their meal came and went without any signs of the missing Princess Celestia. Moreover, it was starting to get late and the sun had curiously not set. It most certainly was not like the Princess to miss a sunset. Trixie was trying her absolute best to keep Starlight’s paranoid fears in check (Twilight must definitely have been giving her panic lessons, it seemed) when she spotted a curious-looking pony out of the corner of her eye in the alley between the cafe and the adjacent haberdashery.
 
“Is that-” Trixie paused, uncertain, getting up from her chair and moving towards the figure “-Princess Celestia?”
 
Starlight’s ears perked up “What? Where?”
 
The pony, wandering aimlessly down the alley, seemingly unaware of its location, definitely bore a striking resemblance to the missing Princess – the proportions were right, tall and slender, unlike most other ponies, but something was definitely off. The mysterious pony was clad entirely in bright yellow rubber with a glossy black coating over the hooves, tail and mohawk-styled mane. Its wings were bound up in tight pods at its sides and it was wearing what could only be described as a gas mask, its breath wheezing in and out of the filters on the sides of its head. Where the cutie mark should have been was a simple radioactive hazard logo.
 
“Celestia? Is that you?” Starlight asked, almost rhetorically. “Why are you wearing one of Rarity’s hazmat suits?”
 
She paused, expecting an answer – or even for, what she assumed was the Princess, to acknowledge they were there. Instead, the pony ignored them entirely, staring blankly at the wall in front of it – a singly forehoof rubbing idly between its legs, producing a quiet squeaking sound as the rubber soles of its hoofboots rubbed against the rubber coating on its underbelly. Trixie reached an uncertain hoof up to tap the pony on its shoulder, in hopes of getting its attention. She gave the pony a gentle prod, but it continued to ignore them, before turning and slowly stumbling away in the opposite direction.
 
“That was really strange, what do you think is going on?” Starlight asked, before turning to face her friend. “Trixie, do you think that was-” She stopped, staring awestruck at Trixie. “Trixie, your hooves!”
 
The hoof Trixie had used to touch the pony was starting to turn a glossy shade of black, the dark patch rapidly overtaking her usual blue coat. Trixie looked back at her friend.
 
“Starlight, your facemmrrmmph?” Her reply was cut off as her mouth was forced shut, much like Starlight’s. Thick strands of yellow rubber spread across their snouts, gluing them shut and reducing their cries of shock to panicked mumbles. Trixie probed at her face with her forehooves, already coated in thick, black rubber boots. With her snout sealed over, she struggled to breathe for a moment as two yellow lumps began to swell from the sides of her face, eventually shaping into a pair of filters which she gratefully sucked air through, producing loud, hoarse wheezes.
 
Starlight clutched her head, starting to feel quite dizzy as the changes worked their way into her mind. She tried to desperately cast some sort of spell to undo whatever magic was working on them, but it quite literally fizzled out as her horn was absorbed into the thick, black rubber mohawk mane that her curly hair was shaping itself into. The world spun as she tried to maintain any degree of focus. She watched as Trixie’s eyes began to gloss over with a faint blue glow, thick rings protruding from around them as glowing blue lenses replaced her friend’s eyes. It wasn’t long before Starlight’s own vision began to cloud, a faint tinge of blue coating the world in front of her. She stared at the faceless pony standing before her – she couldn’t seem to recall their name! Starlight huffed frantically as she suddenly realized she was having difficulty remembering her own name as well. The confused pony fell to her haunches and looked down at itself. Its body was now completely coated in thick, glossy rubber from head to hoofboots. A stripe of black rubber ran down its belly from just below the neck, all the way down to the crotch where a thick bulge hung, pulsing and throbbing with need. It was then that it realized just how horny it was.
 
Yes, it was horny.
 
A horny drone.
 
Its bulge was begging to be rubbed! The pony that was once Starlight couldn’t resist but to reach down with its thick-soled boots and rub itself eagerly. The pure pleasure that rushed to its brain was overwhelming! It seemed so good, so right – this was what it was supposed to do! Apparently the other pony seemed to have figured this out as well and also stood, mindlessly rubbing at itself with a forehoof.
 
The Starlight drone leaned back, laying on the ground, energetically pawing at itself with its forehooves while the Trixie drone aimlessly wandered about on three legs, the fourth never straying from its crotch. Eventually, the Trixie drone wobbled its way on top of the Starlight drone, its bulge brushing against the other’s snout. It paused, while the Starlight drone began to, as if by instinct, nuzzle at the bulge that had found its way to its snout. The Trixie drone looked down, noticing that another bulge just so happened to be right in front of it, laying on the ground. It couldn’t resist leaning forward and pressing its face into it as well. Soon, the pair of drones found themselves in an awkward position, faces pressed into each others’ bulges, both lost in horny ecstasy for what felt like an eternity.
 
They pawed at one another, limbs flailing awkwardly as their bodies squeaked and squirked together, filling the alley with the sounds of their lewdness. Neither was aware of how long they kept at it until they were both enveloped in a magical aura. Neither bothered to look up or to stop rubbing and nuzzling at the bulge before them. Neither noticed the pony standing over them. What they did notice was the incredible pressure that suddenly sandwiched the two of them together. They felt their faces forcefully shoved into the crotch in front of them as the pressure grew and grew and grew. It became difficult to so much as wiggle their legs as the force pressed them into the ground, squishing their bodies together until they were quite literally flattened into a thin, rubber sheet. Still, despite this, the two continued to nuzzle each others’ bulges to the best of their ability. Even as their new, merged form was rolled up and carried away, the horny sheet kept wriggling and writhing gently, softly huffing, moaning and squeaking all the while.
 
Time lost all meaning as the flat sheet lost itself in its perpetual horny bliss. It wasn’t until it felt itself unfurled and laid on the ground that it became remotely aware of its surroundings. It felt hooves press into its back, straightening its form into that of a flat rug – it felt wonderful to be stepped on, especially when the pony standing over it pressed into one of its sweet spots, applying pressure into one of its heads and bulges all at once!
 
Soon the hooves left, leaving the rug to itself, gently wriggling in a futile attempt to enhance its own pleasure. It could have been hours or days that flew by until finally, a new pair of feet would find their way atop the rug… or were they thick, heavy boots? Either way it felt fantastic until a pair of gloved claws grabbed hold of the rug and stretched it taut, tugging and rubbing at it in the most wonderful way! The rug was in pure ecstasy and it couldn’t even see how or why! All it knew is it was horny and wanted to continue feeling this way forever…