She could still remember it like it was yesterday.

It was the previous year, her first estrus season, her first true heat. And life had been miserable.

Having your entire body rebel against you suddenly, as your puberty-enhanced hormones began to cry out for attention for the first time, making a mare’s muscles and organs groan and moan with discomfort. The sweats, the aches, and the Celestia-damned swelling of certain private bits was unbearable.

Even worse were the attitude and mood swings.

Suddenly all the dumpy-looking colts in her class seemed like they were A-list Las Pegasus superstar actors. She had to avoid making eye contact with them or her knees would tremble and her tail would start to lift. She doused herself in deodorant every morning out of the fear that her musk could be detected by others if she got a little too steamed up after passing by a gaggle of nerdy colts.

And suddenly it seemed like every one of her friends were total bitches. They were all out to get her, all out to take her down a peg, to prevent her from getting a hunky coltfriend.

Day in day out, the same intolerable agony.

She’d banged her head against her locker door and let out a long groan of annoyance. Would this intolerable, grinding need inside her never relax? Never switch off? Was this what she had to look forward to every Spring for the rest of her life?

One of those scorned friends came over to her, and gave her a crucial, kindly tip.

And so it was that Trixie had gone to the back-alley secret entrance of Sofas and Quills.

As she entered the clandestine establishment, it suddenly made sense to her how the establishment had managed to be so successful all these years despite its ridiculous business premise.

And why all the mares in town always seemed to be eager to snap up any Quills and Sofas coupons.

Dicks.

Dicks everywhere.

Dildos, vibrators, coolers, of all makes, colors, models and sizes.

One whole wall seemed to be filled with very realistic looking phalluses, each labeled with the names of well-known stallions from Ponyville. She saw that the muscular teenage farmhand of Sweet Apple Acres had a whole shelf devoted to his stock.

“Hi there miss, what can I get for you?” The shopkeeper had cheerfully asked.

Trixie had snatched the nearest object to fall within the range of her telekinetic ability, throwing it onto the counter with a mortified squeak as she pulled her hoodie hood up over her mane and drew the drawstrings tight to shield herself from view.

“Oneofthesepleasethanksbye…” The words tumbled out of her mouth as fast as she could say them, followed by her throwing a bag full of bits on the counter and tearing off with her new package, ignoring the shouted words of caution that the shopkeep had launched her way as she beat a hasty retreat.

It had taken her five minutes to get home, run up her stairs, her hooffalls thumping as she locked her room and jumped onto her bed.

The sheets were still damp and sweaty from the night before. Everything in her room the past few days smelled like her musky plot, which both infuriated and excited her.

Her hoof had not been enough these past few days… no matter how many times she ground the solid edge of her hoof against her aching privates… and she was excited to try out a toy for the first time in her life… to see if it could provide the relief she so desperately wanted.

But as she opened the box she began to realize just how large the toy in her hooves truly was.

Back in the store, it had seemed reasonable… even small… compared to some of the other behemoths that adorned those stock shelves… but here in her own room, in her own small teenaged hooves, she was beginning to realize that slightly-below-average still meant freaking huge compared to what she was thinking of doing with it.

But she would try it.

The press of the cool silicone against her aching wetness made her gasp. The coolness was both relieving and tantalizing. She began to draw the purple sausage up her plot, letting the slick texture rub her in all the new and exciting ways that a non-organic substance would.

The tube was quickly getting a sheen to it, as it picked up some sticky wetness from her body. She wanted to dig it in deeper, press the cylinder into that pleasure-furrow and grind out an orgasm.

But what was the point of the toy then? She could always have simple grinding with her own hoof… this thing was meant to go in her.

She swallowed, looking down at herself once again and chewing her lip.

That tip seemed awfully big.

Just how the hay was something like this supposed to fit inside her? How did mares do that? She’d seen the hole she was aiming to penetrate - it was tiny, not even half the size of a bit!

She was quickly losing her nerve.

But Goddesses did her body want to be entered, to be penetrated.

That’s when it hit her.

Her lower-lips weren’t the only hole her body possessed.

She chewed her cheek in nervous anticipation, then slid the tip down until the pointy end rested at her back-door entrance.

She knew that something this size could pass through the tight little pucker… gross as it was to think about.

Trixie had never been a fan of… poop-stuff.

Like many unicorns her age, she’d quickly learned to use spells to clean and wipe herself after… that. Leaving both her bottom’s exterior and interior as clean as a whistle through the magic of spellcraft.

She had no idea how pegasi and earth-ponies dealt with the same problem. She didn’t want to know.

But now… maybe she had another use for her tailhole.

She began to press inward, the small ponut of flesh slipping slightly open as the pre-slicked toy teased its way into her body.

She shivered, as the relatively cooler end slipped into her hot depths.

Tight.

Like… really tight.

It was stretching her in such a weird way.

A weirdly good way.

*POP*

Derpibooru pic here: derpi booru.org/images/2366482

All of a sudden the tapered tip of the toy slid into her. Sinking past her barrier for the first time. Immediately her sphincter began to tense and squeeze, completely against her control, squeezing the purple toy with a stiff, solid grip, sending strange semi-pleasurable shocks through her body.

She’d thought that her butt would naturally try to push the thing out, given its size and shape… but much to her surprise, it began to slip inwards. Inch after inch of the thick toy being engulfed by her butt, as the clenching movements of her ponut drew the toy inwards very quickly.

Oh no.

Immediately, Trixie began to pull back, trying to halt this scary insertion. Already more of the toy had gone into her than she’d planned. But her hoof was slipping, unable to get a good grip on the well-slicked skin of the toy.

This is bad.

Trixie ignited her horn, hoping to use her telekinetic magic to take hold of the object and make use of the additional purchase to wrench the thing from her body…
This was a mistake.

If she’d taken a moment to read the packaging on the box of her new purchase, she might have noticed the well-labeled text that read.

This is a MAGIC ACTIVATED toy.

As soon as the field surrounded the dildo, it began to warm noticeably and then to hum… then buzz… then vibrate.

Trixie’s eyes flared wide with surprise, and she poured even more magic into her telekinetic field, trying to get the thing out of her as quickly as possible as her whole bottom started to shake from the magically induced vibrations, sending all sorts of new feelings and impulses she didn’t think possible through her nethers.

That’s when the toy, responding to the new surge of energy, began to grow.

Oh, my goddess!

First, the tip inside her began to fatten and expand, stuffing her butt more than she had ever thought possible. Then the shaft thickened, stretching wider and wider with each passing moment, straining the dark blue ponut into a thinner and thinner donut ring as the tight teenage asshole.

She’d never felt so full before. The toy was pressing on all sorts of new walls and angles inside of her, and the buzzing was so intense that it was even making her filly bits start to drool and spatter.

A final, desperate jerk at the dildo was the final straw.

The heat that had been building up discharged all at once, dropping the toy back to a normal temperature as it released the energy stored in a magical pleasure-pulse right into Trixie’s ass.

OH FUCK.

That grinding, winding tightness in her gut broke, snapping suddenly. All the aching restraint and agonizing want, released in a crashing wave.

It surged up her body, like a shiver that started at the base of her spine, racing all the way up to her head and flooring her mind with a pure sense of ecstasy.

Her horn exploded with energy, a crackling whizzbang of firecracker pops and gunpowder smells that sent burning sparks from her horn to singe her pillow.

Her eyes wobbled as her orgasm spilled back down from her brain, racing all the way back to her nethers, gaining strength and speed as it surged back to its source and broke upon her fillyhood.

A powerful clench wracked her. The force of it lifted her hips up off her bed, humping up with intensity against an invisible partner.

Trixie squeaked, feeling her hot little love nub slip out from its hidey-hole, shooting out into the cool air of her room. Her burning, painful lips blossomed and parted as she winked, completely out of control, spraying one, two… three heavy fountain squirts of steaming nectar to her sheets, making a wet puddle of musky filly cum for her butt to fall into.

“F-F-fuuUUuCuKCkK!”

Her scream was loud enough that it would have brought her mother pounding on the door to ask if everything was ok, if she were home.

As her flanks fell into the soaking pool of sticky honey, Trixie finally managed to jerk the toy from her rear.

*POP*

It slipped from her tailhole with an obscene sound effect, before she slung it with a wet thwack against her closet door.

Her ass now free of intruders, Trixie slumped into a shivering pile of wet, post-orgasmic pony. Her left hind leg twitched, entirely out of her control as the aftershocks of her orgasm raced up and down her.

And, in that moment, gasping and desperate for breath, terrified that at any moment her mother could walk in on her shame… Trixie decided that her hoof would suit her just fine for now… and that she didn’t need to be shoving anything into her body, thank you very much.

...not until university at least.

Trixie was desperately studying her hooves, anything to avoid making eye contact with Filthy after answering. She hadn’t told him the story of course… but she still felt like he’d been able to somehow see her mind just the same.

But it seemed to have satisfied him.

He smiled warmly and nodded. “Good, we definitely want to make sure your body is stretched enough to take on somepony of my si- OOF.”

A sharp elbow quickly cut off whatever Filthy had been about to say. “Darling,” The hiss through gritted teeth cut him off completely.

Trixie hadn’t really noticed what the stallion had said nor his wife, she’d been too busy stewing in her own absolute embarrassment, trying to work out if she needed to mention that she’d only put something in her butt. And not where he was probably thinking.

And if she did have to say that, just how the hay she’d be able to say something so incredibly embarrassing. But surely, surely he didn’t need to know that much detail?

She kept silent, merely nodding as Spoiled finished things off.

It seemed like she’d passed the examination, as she started to get into questions that none of her other friends had mentioned to her, about grooming habits, how often she showered, even when she tended to eat… until finally Spoiled had smiled and asked her to stand up.

Trixie had done so, and a quick flick of the older mare’s hoof had sent it slipping under her own. Before she could even resist, Trixie found her tail flipped up over her back. Spoiled apologized… just a slip of the hoof… but when Trixie glanced over her shoulder she thought she spotted Mr. Rich behind her, watching from where he would have had a perfect angle to see her exposed plot. She felt embarrassed, but it was surely just a strange accident, and certainly Mr. Rich wouldn’t have looked.

Spoiled walked her to the door, with Filthy joining her there, nodding vigorously about something as he joined his wife.

The final question had filled Trixie with glee and the sound of bits clinking into her bank account.

“When can you start?”

Author's Note

She got the job! Awesome!

How about that memory though... her butt sure remembers! Poor thing got scared off of insertions though... somepony will have to show her that those things can be quite fun... with practice.