Her parents decided to call her "Deepy" for short. If they tried to call her "Dee," ponies would ask what "D" stood for, and they'd have to give the shameful answer.

They'd treat her like any other filly. All they wanted was for her to be happy and have a normal life, free of any shame or ridicule. And despite her embarrassing name, Oakwood and Peach Seed couldn't help but love her to bits. She was a sweet filly, and very well-behaved. She never cried too much, kept her room clean, always obeyed her parents, and was enormously kind, generous, and eager to meet new ponies.

Especially stallions. As soon as she could run and talk, if it had a pair of balls, she wanted to say hi. Living in Baltimare, this meant that there were a lot of stallions to greet, and even after her parents warned her not to talk to strangers enough that she stopped saying hello to every stallion that walked past, her eyes still lingered on them, and her smile was always bright as she beheld their faces.

It was that they were different from her, and little Deepy was terribly curious. At the tender age of six, she was already asking Daddy about the weird things between his legs as they played together on the living room rug.

"Well," he worked up the nerve, sitting up from lying on his back. It was inevitable. Deepthroat Cockslut liked to look at nuts more than candy, and when Oakwood's impressive set already kept his thighs more spread than the average stallion, it was only a matter of time before she asked. "Those are my testicles," he explained. "All stallions have them, and they're used to make foals with mares."

"Huh," she said. She stared at her father's balls for a while longer, and already the sweat was trickling down his neck as Peach Seed looked up from her book, nervously awaiting their daughter's response.

"They're very sensitive," Peach Seed said after a beat. "And it's not polite to touch stallions there."

"Yes, Mommy," she said sweetly.

But this new information only ignited her curiosity. In the naked world of Equestria, Deepthroat Cockslut had plenty of sack to stare at, and stare she did. Her parents tried to teach her manners, that it wasn't polite to stare and it was best to ignore them altogether, but she couldn't help it. Nearly every day she went out with her parents, she had at least one comment to offer on a random stallion's genitals. She thought they were all great, whether they were big or small, hairy or smooth, sweaty or clean. It was sweet in a way, but mostly concerning for her parents.

So when she started school, she was told at least a hundred times not to talk about or look at any of her classmates' testicles.

"Yes, Daddy," she said.

For the most part, she couldn't help it. The colts her in class were so much smaller than stallions, in all ways, but she did as her parents told her and kept her mouth shut. Unless they were playing doctor, of course. That was her favorite game.

She got a few complaints from parents, and there were some parent-teacher conferences about appropriate touching, but the teachers always assured her parents that it was normal for little Deepy to be curious at this age, and that it was purely innocent. And for the most part, it was.

Until she turned eleven.

Almost everypony had their cutie marks at this point, and she was the last in her class, to her great shame. Even if she was friends with almost every colt in the class, the other fillies still called her a blank-flank, and the colts couldn't really protect her. Her parents told her that she was simply a late-bloomer and that it would come when it was time. But that didn't stop everypony from worrying about it, especially her parents. When cutie marks and names tended to go hoof-in-hoof, they were plagued with nightmares about their daughter coming home with a lewd image on her flank. A name could be shortened. A cutie mark was immutable.

One of her closer friends, a brown colt with a red mane named Sawdust, had already gotten a cutie mark for lumberjacking, and as was appropriate for the profession, had begun getting large growthspurts at the age of twelve. Deepy had grown, but he was a good head taller than her, and already putting on muscle.

All of these changes were fun to monitor. So when he galloped up to her in the schoolyard and said in a cracky, pubescent voice, "Hey, Deepy! Wanna play doctor?" she only had one answer.

"Of course!"

Lots of other ponies had outgrown the game of pretend, so the patch of grass behind the toy shed was usually abandoned. Sawdust was the only colt who still liked playing this game, and she felt like hugging him just for suggesting it.

"So who's gonna be the doctor?" he asked.

"I want to!" she jumped on the opportunity.

"Alright," he chuckled.

They found a Y shaped stick for her to wear around her neck like a stethoscope, and once she was in character, she said, "Time for your checkup young colt! Lay down on my table."

Sawdust laid down on the patch of grass, and Deepy made a big show about poking his with her "stethoscope" and going "hmmm." After she had done this for long enough, she said, "Okay, now let's measure you." Without a measuring tape, she just stretched her hooves out and moved alongside him until she reached his head and hindlegs. "You're getting almost too big to measure, Sawdust," she said.

"My dad says I'm gonna be a big stallion," Sawdust admitted proudly.

She poked at his arms a with her hooves. "Your muscles are getting really big."

"Really?" he said with a blush. He couldn't help but flex for her.

She squeezed his biceps. "Yeah. You must be the strongest colt on the playground," she complimented.

All of her praise and touching left Sawdust feeling warm and comfortable. So when Deepthroat Cockslut continued her checkup, it wasn't a total surprise to her to see that his penis had slipped out of its sheath. Being the experienced doctor that she was, this was not the first penis she had ever seen, but normally they didn't slip out until she gave her testicle exam.

But, for the sweet little filly, nothing was amiss. "Your wiener's getting really big too," she said.

"R-really? You think so?" Sawdust said, even more nervous and flattered than before.

"Yeah. I can barely fit my hoof around it," she said, giving the thick black shaft a squeeze.

"Ah," he gave a little moan.

Deepy hardly noticed, still preoccupied with the change in her friend. "Even your balls are bigger. And do they usually hang so much?" The sweet filly rolled the orbs around in her hooves.

"I- I don't know, but that feels really good," Sawdust told her.

"Really?" she asked. Colts normally said they liked being touched there, but this was a different kind of pleasure. "How good?" she said, fondling him further.

"Really really good," he admitted. His pre-teen cock had more than just flopped out. It was standing tall and diamond hard, something that Deepy hadn't quite seen in her time.

"Is it supposed to do that?" she asked.

"Yeah. It's been doing that a lot lately," he told her, just as clueless as she was.

"Huh," she said. "And it feels good when I touch it?" Sweet little Deepy started to rub Sawdust's erection.

"Yeahhh," he moaned. There was a moment of silence where all that could be heard was the chirping of birds, laughing and shouting foals, and Sawdust's heavy breathing as the little pink filly played with his dick.

"What else feels good on it?" she asked.

"Baths," he answered. "They're so warm and wet. They always make it get hard."

"Huh," she repeated again. Deepy didn't feel the tug of Destiny on her, but she still answered its call with her next words. "My mouth is warm and wet."

"You- wanna lick it?" he asked.

"I mean, if it doesn't taste bad," she said. "Do you think that would feel good?"

"Yes," he said quickly. "I mean, if you want to."

"Why not?" she said. Without an ounce of hesitation, she leaned forward and gave Sawdust's stiff, throbbing tip a long, loving lick.

"Ohhhh," he moaned loud.

"Was that good?" she asked.

"Deepy, that was really good." He was already panting, from pleasure and adrenaline. "Can you do it again?"

"Sure," she said. Another long lick, this time more along the shaft, wetting it with droplets of her saliva. It tasted mostly fleshy, and maybe a little salty, but she loved the smooth texture, and the way it twitched at her ministrations. "This is fun," she admitted.

"Hey, I just got an idea," Sawdust said, grinning eagerly. "What if you put it in your mouth?"

"Like, suck on it?" she asked.

"Yeah," he said.

"Okay!" she said. His excitement was wearing off on her, and she was starting to feel some of his warmth, especially between her legs.

Lining up the shaft with her hooves, she held over the tip, watching the flare throb, seeing some clear, sticky liquid pour from it. But she knew it was safe. Sometimes she made almost the same sticky stuff from her private parts, too.

In that moment, Deepthroat Cockslut was in her element. Her curiosity about what it would feel like to both of them was overwhelming, and she wanted to know about taste and smell and just about everything else too. Her natural generosity was taking over too, as she wanted nothing more than to make her good friend Sawdust feel as good as he possibly could. His moans already made her so happy. But at the same time, touching him and licking him made her happy, too. His hard shaft felt good to her hooves and mouth, and something very deep inside of her wanted more of it.

So little Deepthroat Cockslut opened her mouth wide and wrapped her lips around the head of the dick before her. Her first blowjob.

"Ohhh yeah," Sawdust moaned, louder than before.

She stopped for a moment, pulling off. "That sounded like it felt really good."

"It did," he said. "Keep going. Please?"

"Do you want me to get further down? Will that feel good?"

"Yes. Please. As much as you can." The desperation for pleasure in his voice was obvious, and she didn't want to keep him waiting.

She took the tip into her mouth once more, licking along it with broad strokes that earned more creaky, pleasured noises from Sawdust. Deepy had no trouble going further. Somehow, she knew to keep her teeth tucked behind her lips. She had been told how sensitive stallions could be down there, and the last thing she wanted was to hurt her friend. She didn't have to be told to twist her head or swipe with her tongue as she took inch after inch of horny teenage cock into her mouth.

But the real magic was when the head reached the back of her mouth. As if she had been doing it all her life, Deepthroat Cockslut took it further, gaining inch after inch of meat, until the cock was deep in her throat.

Now both of them moaned. Sawdust had never imagined his cock could feel this good in a mare's mouth, but Deepy had never imagined how good a cock could feel in her throat. She felt an amazing fullness, a glorious stretch, that filled her with more and more warmth, her mare parts producing wetness for her first true moment of arousal.

"Oh, Deepy... Sweet Celestia," Sawdust moaned. But Deepy kept going, wanting more of his hot flesh, more of this wonderful, hot, full feeling, wanting more cock in her.

She reached the bottom. She felt her lips bump against his fleshy sheath, barely fuzzed with new pubes, and she felt his eager, young balls resting warmly against her throat.

She was full now, twisting, licking, and sucking happily on the cock before her. And it was the best feeling in her life.

The same went for Sawdust. "Deepy! Something's happ- Ah!" he cried.

Deepy didn't know what was happening. She felt Sawdust's cock pulsing, the flare swelling, the excitement building, and it only made her more excited, and she sucked all the more hungrily. Suddenly, a warm, salty fluid poured into her throat, backflowing into her mouth a little. It was strong, earthy, heady; like nothing she had ever tasted before. But it was delicious. It tasted as good as the cock felt, as good as Sawdust's cracking, ecstatic cries were to her ears.

She drank it with relish. She wanted more. His penis filled her with such incredible warmth, such a fantastic pressure, it felt like she was going to explode. Every gulp of the sticky stuff filled her with such a burning joy that she didn't want to hold it in anymore.

Her body tensed. She would have told Sawdust that something was happening to her too, but that would have meant releasing his cock from her hungry, loving muzzle. But as she drank the last drops of him, pleasure began to overtake her, moans rippling from deep in her throat as she shook, her tongue and lips never ceasing their attention.

With her own cute cries, Deepthroat Cockslut reached her first orgasm, just as Sawdust had. Her body was racked with fiery, electric spasms, and her mind went blank with pleasure. All the felt was the wonderful feeling of being stuffed full by a thick stallion; of belonging.

Through the dizzy haze of her pleasured mind, she heard Sawdust saying, "Stop." She pulled away from him. He was breathing hard. Just as hard as she was. "That was amazing," he said.

"I know," she said. "It felt so good, and it tasted so wonderful." She saw a few lingering drops of white on the tip of his shaft. "I wonder what that is."

"I dunno," he said.

Deepy licked the drops from his tip, earning a sharp gasp. She hummed when she felt that delicious salty taste spread on her tongue. "Mmm."

"I didn't know that could happen," he said.

"Me either," she said. "Wanna do it again?"

"Yes please," he said. The eager colt wrapped his hoof in Deepy's curly blonde mane and pulled her head toward his cock. But she accepted the offering all to eagerly, more than willing to suck dick once more.

Over the course of the recess, Deepthroat Cockslut earned two more orgasms from Sawdust, swallowing each load in the midst of her own climax. When the bell rang, his cock was buried into her muzzle all the way to the sheath.

"Wanna do this again tomorrow?" she asked as they headed back to class.

"Yeah," he said with eager nods. Then he gave her a puzzled look. "Deepy- look!" he pointed at her flank.

Sure enough, Deepy's butt was adorned with the image of a golden-yellow rose.

When the teacher, a kindly old mare, noticed it, she brought her up in front of the class, thinking she got it picking flowers. "Would you like to tell the class how you got your cutie mark, Deepy?"

"Yeah! I got it sucking on Sawdust's wiener!" she said enthusiastically.

With a note home to their parents and another parent-teacher meeting scheduled, Deepy and Sawdust were told never to do that ever again. And, for the most part, they managed to cut down on the cocksucking to about once every other week. But with colts maturing and starting to realize how good such a thing would feel, Deepthroat Cockslut suddenly found very many friends willing to play doctor. The other fillies didn't take kindly to her, and her parents and teachers took all measures to stop her from sucking dick, but it didn't matter.

Deepthroat Cockslut had discovered what she loved most in the world, and nothing could keep her from it.