The prestigious Clover Institute for Medical Science is a highly respected, well-funded, well-equipped research laboratory in Canterlot City. Every year, hundreds of scientific studies are conducted at Clover Institute—everything from clinical trials of new medications to behavioral studies, all with the purpose of increasing the understanding of medical, behavior, psychological, and other less quantifiable sciences for the betterment of humanity.

Even sexuality studies are conducted at Clover Institute. Some of them may not seem to have much scientific merit, but anything that can help people live healthy, active, productive lives—even if it just means a healthier sex life—is encouraged by the Institute.

Of course, research studies need volunteers. Our latest sexual health study is searching for individuals in the age range of 18-25...

The pamphlet from the Clover Institute had materialized in the mailboxes of every home in the Greater Canterlot Area on a Tuesday afternoon.

Much to the consternation of the faculty of Canterlot High, it was all most of the senior class could talk about all day on Wednesday. Including one table in the cafeteria occupied by nine girls who, judging by the varying shades of red and looks of interest or embarrassment on their faces, had very different opinions on the whole thing.

Twilight Sparkle's eyes lit up. "I've always wanted to visit the Clover Institute," she said. "It'd be so exciting to see actual scientific research being performed!"

Applejack arched an eyebrow. "Uhh, Twi? That 'actual scientific research' is gonna be a buncha perverts watchin' gals our age git roto-rootered."

"They're hardly perverts, Applejack," Twilight scoffed. "They're professional medical researchers! It's a clinical study, not a...a porn theater!"

"But they will be watching a great many young women engaging in, ahem, backdoor activities," Rarity pointed out.

"Well, yes, but sexual behavior studies aren't indecent, they're beneficial!"

"Uh-huh." Applejack glanced at Sunset Shimmer. "What do you think of all this?"

Sunset shrugged. "Hey, where I come from, what two consenting adults do behind closed doors is their own business," she said. "I mean it's not like sex is some big huge secret or anything, it's just that nopony cares. But this world has like, entire industries devoted to sex. Prophylactics, medications, lubrication, toys..." She shook her head. "That's not even starting on porn, prostitution—"

"We get it, darling," Rarity said archly.

"Well, I'm gonna go for it!" Pinkie Pie announced cheerfully.

The girls all stared at her incredulously. "Seriously?" Rainbow Dash asked.

Pinkie shrugged. "What? They'll give me five hundred bucks to do something I was probably gonna do one day just for fun anyway. Besides, it wouldn't be the worst thing I ever did for science."

The girls looked at each other, expressions of nausea and dread crossing their faces. Finally, Sunset groaned. "Okay, somebody has to ask," she said in a resigned tone. "What's the worst thing?"

Pinkie's face fell, her voice becoming small and distant. "Watching paint dry," she said tonelessly.

The others blinked. "I-I beg your pardon?" Rarity asked.

Pinkie hugged herself and shuddered. "They made me sit all alone in a tiny room. No phone. No snacks. Just a wall covered in wet paint. I had to sit there and watch it dry. No talking, no singing, no games, no fun."

Applejack raised an eyebrow. "An' how's that science exactly?"

Pinkie's shoulders lifted slightly. "I'unno," she mumbled. "Something about kids with attention deficit disorder, concentration..." She gestured vaguely. "Though now that I think about it, maybe it was less a for science thing and more a my parents thought I was too hyper and were trying to fix me thing."

A long, awkward silence followed that statement.

Suddenly, Pinkie returned to her usual cheer, seeming to inflate like a dozen balloons as she beamed brightly. "So anyway yeah, gonna get paid to take a pecker up my pretty pink party pucker!"

The rest of the girls' faces slammed against the table.

"You know, I don't think I'll ever get used to Pinkie Pie," Wallflower Blush said.

Sunset laughed. "That's okay. None of us ever get used to Pinkie Pie." She drummed her fingers on the table, looking around at her friends. "So, umm..."

"Nope!" Rainbow said. "Sorry, but uh..." She snuck quick glances at each of her friends. "I mean, I know I've kinda got a dirty mind like, ninety percent of the time, but I don't really wanna know which friends of mine are gonna whore out their buttholes at this place. That's like...I just don't need to know that, y'know?"

"I agree," Rarity said prissily, tossing her hair. "This entire ludicrous affair is beneath contempt and beneath notice."

"The Great and Powerful Trixie prefers to keep her Great and Powerful Anus confidential," Trixie put in unnecessarily.

"I wonder what they're gonna do about male volunteers, though," Wallflower said absently. "I mean, it just says 'persons' on the flyer, what's up with that?"

"Well, it stands to reason they'll need men who've never had anal intercourse," Twilight said. Blushing, she clarified, "I mean, men who've never performed it on another person, not, y'know..."

"Guys who never took it up the butt before?" Pinkie suggested.

"Yes. Yes, that." She paused. "Or, I guess maybe that too? I mean, such a study shouldn't exclude homosexuals..."

"Or bisexuals," Sunset noted.

"Ah thought we were done talkin' about this?" Applejack said in a warning tone.

* * * * *

Principal Cadance pinched the bridge of her nose and shook her head as yet another member of her faculty ranted and bitched about the Clover Institute pamphlet.

"—insult and disgrace to the reputation of Crystal Prep!" the stuffy old twat was saying. "Why, if Abacus was still here—"

"Well she's not," Cadance snapped, holding up a slim pink hand. "And quite frankly, Professor Gourmand, what our students do in their private time, outside of school hours, is no concern of mine as long as it's legal and not dangerous. As long as these kids aren't having anal sex in the halls of Crystal Prep, it's not my problem." She fixed Zesty Gourmand with a stern stare, raising one slim eyebrow. "Are my students having anal sex in the halls of Crystal Prep?"

Zesty Gourmand gave her one of those looks that SCREAMED 'I have smelled cat feces less odious than you' and spat out, "No. They most certainly are not."

"Then if they want to go to the Clover Institute—which, incidentally, Crystal Prep has a long-standing and agreeable relationship with—and get railed up the back door, it's not really any of our business."

"But...but there is discussion of it!" Gourmand rallied, pounding a fist on the desk.

Cadance raised an eyebrow. She slowly reached for the intercom button.

"Kids? This is Principal Cadance. If you want to talk to each other about the Clover Institute thing, please do so over text message. That way, your professors won't burst into conniption fits. Thank you, have a lovely Wednesday." She released the button and folded her hands primly. "Better?"

Zesty Gourmand stood, taking deep, heaving breaths. She ground out something about Cadance, the Clover Institute, and a broom handle, then stormed out stiffly.

Cadance shook her head, blew on her bangs, and studied one of the pamphlets. "I wonder if they'll take a twenty-nine year old? I could use a little destresser..."

* * * * *

Ten days later, a group of research students and two tenured researchers met up at Clover Institute's Sexual Health Studies Clinic. The project leader, Dr. Grinder, looked over the applicants list and nodded. "The turnout was higher than expected," he said. "Good."

"It's going to stretch the grant, paying off this many volunteers," one of the students said nervously, biting her lip.

"As long as we get the data we need," Dr. Grinder said.

"With this much variety in respondents, we should be able to get more data than we'll know what to do with," said the senior researcher on staff, Dr. Van der Høver. He folded his hands in front of his face and grinned. "Let's get the first group started..."

Author's Note

And so begins another Equestria Girls clop anthology, albeit one with a more narrow focus, a clearly defined excuse plot, and a more-or-less finite lifespan. This was supposed to launch in the summer of 2017, but the very same week I came up with it, Hurricane Harvey decided my neighborhood needed to be a lake, and that kind of derailed things. Took me a year to get around to resurrecting it.

What you, the reader, need to know:
- Each chapter will feature one (female) Equestria Girls character.
- Male EG characters may guest-star as, ahem, research partners.
- Even though the formula for this story has been established, there's nothing saying other things won't happen in those clinic rooms...
- This story will be bumpable during Mature Month for my Patreon patrons.
- Otherwise, this story will be updated when I feel like writing buttsex.
- I will not be taking requests from readers in the comments section. Don't even bother.