The train car rattled and clacked as it rolled along the tracks. Twilight stared out the wide glass window, leaning her elbow on the wall and cradling her chin in her palm. She watched as fields, farms, and trees went past, the Equestrian Express chugging steadily down toward Ponyville.

She wasn’t entirely sure how she felt. Not because she was returning home—she was overjoyed at that, though somewhat bemused at just how much she considered Ponyville “home” these days. Her mouth creased slightly as a grove of trees sped past the window.

In the window pane, she spotted the reflection of one of her new wings. It twitched, bright purple feathers brushing against the leather seat. Twilight grimaced. That was what she wasn’t sure about.

Sixteen hours ago, she’d been coronated. Announced as a Princess of Equestria before the entire population of Canterlot. Forty hours prior, she’d solved a mystical, century-old spell, blacked out, and woken up with an entire new set of appendages. She felt her feathers brush against Fluttershy’s shoulder and shivered. She hadn’t expected just how sensitive they would be.

Her friends had been supportive, sudden as the transformation might have been. She’d leaned on them so much for confidence during the coronation, and now, all she wanted to do was live up to their expectations. Thankfully, her friends didn’t expect much more of her on long train rides than to curl up and stare thoughtfully out the window, which left them time for other activities.

The six of them were clustered into a train booth, nestled so tightly that a twitch could send Twilight’s elbow flying into Fluttershy’s gut. The other five didn’t seem to mind the closeness, though. They had something much more interesting in mind.

They were gossiping.

“—the most wonderful stallion, really,” Rarity was saying. Twilight’s ears flicked up as she tuned into the conversation, and she smiled. Of course Rarity would be discussing romance. “He gave me his address for correspondence, and—oh! I simply can’t wait to write him.”

“You met him at the afterparty, huh?” Rainbow was reclining in her booth, both hands clasped behind her head. Her wings flared out behind her, leaving Applejack beside her both slightly squished and more than slightly flustered. Dash leaned forward and grinned, rubbing her thumb and forefinger together. “Y’know what he wanted, right?”

Rarity stared at her for a moment. Then she flushed. “Excuse me, Rainbow Dash,” she said. “But not everypony in Equestria is a slave to their...baser desires as you are.”

“Puh-lease,” Dash scoffed. “Dude’s a colt. I’ll bet he had one thing in mind last night.” She winked at Fluttershy, who blushed a bright red. Then, she jerked a finger at Rarity—or, more specifically, at Rarity’s well-endowed chest. “Bazinga.”

“Rainbow!” Rarity said. “How dreadfully disrespectful! He was a perfect gentlecolt!”

When Dash snorted again, Applejack turned to give her a level stare. “And I’m sure y’all know all about colts, don’tcha?”

“Oh, you bet,” Dash said. She smirked and punched her hand into her other palm. “See, I’ve been with more than enough stallions to know what they’re lookin’ for. They talk pretty, but what they really want is a little bit bigger than handholding.”

Rarity sighed. “Which is?”

“Duh,” Dash said. “Sex.”

Fluttershy squeaked. Pinkie giggled. Rarity fumed.

“And you would know, I’m sure,” Rarity said, sniffing.

“Oh, man. You’ve got no idea.” Dash leaned back in her seat and folded her arms underneath her ample chest. Twilight couldn’t help but notice the way her bust squished against her forearms, or the way Dash seemed to smirk right at her as she said, “See, when they see a hot mare, stallions know what they want. And I know they know, so I know how to give it to ‘em. They start out putting their hands on your hip, then before you know it, it’s in your pants. And then you start getting a little bit closer, and you just know that they’re ready to—”

“I—but—Rainbow Dash!” Rarity sputtered. “That’s quite enough!” Dash stopped short and smirked, though she had the grace to look a bit sheepish when Fluttershy squeaked again with cherry-red cheeks.

“Buncha prudes,” Dash grunted. She flopped back in her seat.

Twilight’s cheeks were flaming, too, though not quite for the same reason as Fluttershy. From the minute Dash had started painting that very interesting picture, some part of her had responded.

Something new.

“Excuse me,” Twilight mumbled. She stood up and hastily pushed her way past Fluttershy and Rarity. “I, um, need to go to the bathroom.”

“Oof! Um, of course!” Rarity said after her.

Twilight could hear Dash cackling behind her as she walked. “See?” Dash was saying. “Hot and bothered. If only the rest of you weren’t so—”

Twilight shut her out after that. She was too busy trying to ignore the growing dampness in her panties, trying to conceal the swelling bulge at her crotch. She hoped that nopony had noticed it when she’d stood up—oh, she prayed Rarity hadn’t felt it when she’d jostled her leg. It throbbed against her thigh and she bit her lip. She walked quickly, stiffly, then regretted that when she felt something long and hard snaking its way down her leg. She tensed her thigh in response, and succeeded only in stimulating the bulge further. Twilight swallowed as she (rather rudely) brushed past a pair of mares who looked very excited at the sight of Equestria’s newest alicorn, refusing to make eye contact. She looked like a mare on a mission—which, in a way, she was.

The bathroom. Yes. Thank Celestia she’d made it. Once inside, she quickly shut the door behind her and locked it. She didn’t open the top of the toilet seat, just sat down with her hands on her thighs.

Below her, the train car rumbled on down the tracks. Her focus was entirely on her lap, though—and on the long, thick bulge snaking down toward her knee. She gave one thigh a squeeze and grunted softly. A new spot of dampness bloomed in the fabric of her slacks. With trembling fingers, she reached down and slowly unzipped her pants.

As soon as it had the available space, the source of the bulge bounced up into the air, far too large to be constrained by her tight, lacy panties. Twilight felt it smack against her belly and grunted. She winced at the sight of the smear of pre across her blouse—and that was a new one, too! Darn it. She’d have to clean that off too.

She turned back to her new...equipment. Licking her lips, Twilight briefly reflected on the ludicrousness of her situation. Upon ascension, she’d been awed to receive her new wings. Not surprised, though—everypony knew that alicorns had wings, and she’d been honored to find them. What she hadn’t known, though, was a secret that Celestia had very carefully kept from most of her subjects for centuries.

Alicorns were hermaphrodites. And they were extremely virile.

The edge of her palm brushed against the side of her shaft, sending tingles of pleasure up her spine. Twilight stifled a moan. Maybe it was her body adapting, or maybe it was a simple fact of alicorn biology that she’d have to grow to live with. Whatever the case, she’d quickly discovered two things about her new body. First, she was very, very sensitive. Second, she was a bit of a hair trigger. The smallest lewd fantasy sent her mind spiralling down into smutty thoughts; the lightest brush against her crotch left a half-chub throbbing in its wake.

She’d been very relieved to discover that her coronation outfit was a poofy, oversized, old-timey dress. It had done a wonderful job of concealing her entire upper body—even the oversized chub that she’d walked around with for most of the ceremony. She’d kept control of herself for most of that morning, and (she was proud to say), all of the afterparty that followed. Her panties had been utterly ruined by the end of it, though; not even a max-power cleaning spell could’ve washed out that much precum.

As she took her cock in her hands, she almost groaned in relief. The sides were slick with pre, and the shaft was long enough for her to fit both hands atop one another with room to spare. She actually had some difficulty wrapping her fingers all the way around—from measurements she’d done in her bathroom last night, she was five inches soft, ten inches hard. And thick.

As she jerked herself off, Twilight found her thoughts drifting to dirtier and smuttier places. Masturbating was quite fun—and very pleasurable, and very messy, as she’d discovered in her bed two nights ago—but she’d had sex with a few ponies before, and she couldn’t help but wonder how her new equipment would function with the aid of another. Her partners had, admittedly, been mostly study buddies from Canterlot, but she’d held no illusions about their relationship—casual sex was far from unknown in the city, and she’d been grateful to lose her virginity in exchange for a few measly math problems.

Her strokes sped up, and her breaths got heavier. She’d taken a stallion’s cock more than once before, but oh—how would it feel to be on the other side of the equation? To penetrate, to fill, to stuff a mare (or stallion, she wasn’t picky) with her meat and essence? Twilight found herself licking her lips, then gasping softly as she jerked her hips in time with her strokes. She could feel her nuts, each one the size of a golf ball, withdrawing toward her crotch as she approached the inevitable peak—

With a moan, Twilight came. Her back arched and her stallionhood flexed. The entire shaft lurched backward, splattering the underside of her breasts with cum. Her breath came in short, sputtering gasps, eyes fluttering as shockwaves of pleasure went through her system. Splurt after splurt of thick, gooey cum stained her blouse, dark, gooey ropes of spunk covering her lap and her belly.

She sat there, leaning against the cool, metal bathroom wall as she slowly inhaled and exhaled. The warmth of afterglow slowly spread through her body, her groin relaxing as it recognized its satisfaction. One of Twilight’s hands released her shaft and fell to her side, fingers dripping milky-white pre and thick ropes of spunk; the other clung limply to the base, her fingers digging into the hard, meaty surface of her new toy.

But who would help her? she wondered. She wasn’t that close to anyone in Ponyville, and if Rarity’s attitude was anything to go by, casual intimacy just wasn’t a thing in a village with a population of fewer than five hundred ponies. Which made sense, to a degree. She just wished she knew somepony who might have been willing to help her work off a little steam…

If they hadn’t been drenched in slick, sticky jizz, she would have snapped her fingers. Of course! Twilight’s mind rewound to the conversation that had sprung her erection in the first place. Rainbow Dash! Maybe everypony else in town was a prude, but surely a headstrong, free-spirited pegasus like Rainbow would be willing to lend her a hand! And, while Twilight wasn’t the most well-read on male sexual biology (a fact she was going to change at the nearest possible opportunity), she knew enough from experience to see that she was at—if not over—the far end of the bell curve when it came to size, not to mention output. For all she knew, Rainbow would love to boast about conquering a Princess-sized cock.

Twilight blushed. Though, given the nature of the community, they might want to keep that on the down-low. Friends with benefits was what she’d be looking for, and that wasn’t exactly something she’d want to have trumpeted around town. Still…

Rainbow Dash wouldn’t have been far from her first choice, anyway. Cocky, confident, and athletic, the lithe pegasus just oozed sexuality. Even before she’d gotten her stallionhood, Twilight had always eyed Rainbow’s toned, sculpted body with a note of awe and envy. Now, with her more masculine urges egging her on, she would’ve loved the opportunity to pinch that tight bottom, or to grind her thick shaft against those rock-solid abs—

The blush returned. But first, she actually had to make the offer—which she couldn’t very well do in her current position. The train car lurched around her, and Twilight quickly remembered where she was. A quick spell cleaned off her lap and hands; another returned her blouse to a pristine sky-blue. And her balls felt at least marginally emptier, she noted with a smirk in the mirror as she zipped herself back up. Which meant that the rest of the ride was likely to go off without a hitch.

And it did. Thankfully. She returned to her seat with a bounce in her step, and engaged in the conversation with a new kind of vigor that even Applejack noticed. All the while, her eyes kept flicking toward Rainbow Dash—not only her face, but her chest, and her lap as well—while outside the Equestrian countryside sped past them, the sun slowly burning its way down through the afternoon sky.

When they arrived in Ponyville, Twilight said her goodbyes, gathered up her things, and jogged back to the library.

There, she wrote a letter, and had Spike send it shortly thereafter.