After a while of searching through different hallways, the two eventually came across the same one, finding the perfect path. No one was going down it, and it was also pretty far from the other more busy halls. They both looked over to each other, grins slowly forming on both their faces.

"I'll make it back before you!" Rainbow cried before she took off.

"Hey! No fair!" Pinkie called out as she chased after her.

Rainbow speeded down the halls, rushing up some stairs to get back to the library. She even took a brief moment to look behind her, finding her friend just reaching the stairs.

"Looks like you'll be the one doing the butt kissing this time!" The jockette declared, quickly mooning the party girl at the bottom of the stairs.

Pinkie quickly found herself entranced by Rainbow's booty. "Ooh!" she said as her eyes widened, like she was eyeing a piece of tasty candy. "Ok!"

Rainbow laughed, her knees pointing inward as she wiggled her large blue bottom from side to side. The flesh on the athlete's butt cheeks jiggled as she shook it.

Pinkie quickly zipped up the stairs until she was directly in front of Rainbow's behind, she kneeled before it like it was a precious object.

"Oh great and glorious Rainbow Dash, would you do me the honor of… kissing thy glutes?" Pinkie Pie asked while talking like she was in an old fashioned play.

Rainbow looked behind her, finding her friend already kneeling right by her big blue butt. She smirked, wiggling her tush in front of her face. "Pucker up, Pinks! Make sure to give it a nice big wet one!"

"With pleasure!" The party girl declared as she licked her lips, puckered them and pressed them against Rainbow's bottom as hard as she could, creating a loud, wet noise in the process.

Rainbow shuddered a little bit at first but continued to grin while her friend gave her a literal ass kissing, reveling in the payback she was getting from last time.

"That's right. Kiss my big blue ass, Pinks!" Dash declared before she heard footsteps coming their way, making her gasp and her eyes widen, "Uh-oh! Someone's coming! We gotta go!"

Pinkie quickly removed her face from Rainbow's ass. "Aw! But it's so tasty!"

"We can resume that later, right now I don't wanna meet the same fate as Rarity might." Rainbow Dash reasoned.

"Aw, okay." Pinkie whined, she grinned when she saw the kiss mark on Dash's cheek. Rainbow quickly pulled up her lower garments.

"Let's head back." Rainbow stated before heading back to the library, with Pinkie following behind her. The party girl's eyes were firmly locked on Dash's butt as she walked, and she licked her lips hungrily at it.

Soon, the two of them returned to the library, finding the rest of them chatting.

"No way!" Sunset said.

"Uh, huh. I sure did." Applejack responded, smirking proudly.

"Oh… Right in front of their whole team?" Fluttershy inquired.

"Whoa, whoa, what are we talking about here?" Rainbow asked curiously, joining them at the table.

"AJ was just telling us about the time she mooned the Shadowbolts." Sunset Shimmer revealed.

"Aw! We missed it?" Pinkie whined.

"It's not that long of a story, Pinkie." Applejack stated.

"Well, let's hear it!" Rainbow grinned excitedly, while Pinkie sat next to her.

"What about the halls?" Sci-Twi pointed out.

"And the time! We're going to be late for class!" Rarity realized.

"Clear for now." Rainbow reported.

"Then let's go!" Applejack declared.

"Aw, come on!" Rainbow complained, as everyone got up in a hurry.

Everyone darted off to whatever class they had at the moment, splitting up.

Rarity arrived with Sci-Twi at her class, luckily just a few seconds before the late bell rang.

"Phew, that was almost too close." Rarity said, a little exhausted from running right to class.

"You're telling me." Twilight replied, panting. They both sat down at their seats, being right next to each other. It wasn't long before the teacher began rambling on whatever the lesson was for the day.

Rarity was trying her hardest to stay awake but due to her exhaustion she quickly found herself dozing off. It was only until the bell rang again which awoke her, and made her realize she practically slept through the whole lecture. There was nothing she could do about it now, so she simply grabbed her belongings and headed out after everyone else did.

Just as she left, she almost jumped when she found Twilight standing right outside the classroom, waiting.

"Oh, hi there. Sorry for surprising you." Twilight said, sheepishly.

"No worries darling, didn't look where I was going, that's all." Rarity assured her.

"Well… actually… I've been waiting for you." The techie girl admitted, adjusting her glasses.

"Waiting for me? But why, darling?" Rarity inquired.

"Uh… you see I… have a request." Twilight revealed.

"A request?" The fashionista echoed.

"Yes. I… want to… study your gluteus maximus." Sci-Twi finally said, blushing.

Rarity stood there for a moment, not quite sure why her friend had this sudden request.

"I'm sorry dear but… did you say you want to… study my… derriere?" Rarity spat out, baffled.

"Y-Yes…" Sci-Twi nodded, flushed.

"May I ask… why?" Rarity questioned, raising a brow.

"Well… it mainly has to do with both scientific curiosity and… personal curiosity." Twilight confessed.

"Come again?" Rarity asked, still confused.

"I want to know just what it is about the glutes of a human that Rainbow Dash and Pinkie Pie find so funny, and why people are attracted to them so much. Not to mention how someone like you can be so… aroused by activities involving it…" Twilight explained.

"Ah, I see…" Rarity said, sort of understanding where the nerdy girl was coming from.

"I know it sounds weird, believe me, but I just have this feeling that my curiosity won't be satisfied until I find out for sure." The glasses wearing girl stated.

Rarity thought about it deeply, this was a lot of information to take in at once. However, she decided in the end to let her friend follow her curiosity. "Sure, but we have to be quiet about it." Rarity told her, quickly looking around just in case someone might've heard them.

Sci-Twi nodded. "Right. Come to my lab after school, we'll do it there and no one will bother us. Promise."

"Deal." Rarity nodded back before they both shook hands.

"Good, see you then." Twilight told her, waving before leaving. Rarity gulped as she thought about what might happen before leaving herself.

---

It was a little past an hour since school had ended, Rarity had went home and picked a new skirt and finally was able to put on some panties again, after which she went straight to Twilight's house.

She stopped in front of the door to the shack where Twilight's lab was inside, it had a keyboard next to the door and lights flashed through the windows above. Rarity was a little unsure of what to do next before she pressed one of the buttons.

"Um… Twilight?" she spoke up. Much to her surprise, she heard Twilight's voice coming from it like an intercom.

"Rarity?"

"Yes. It's me, darling. You told me to meet you here after school." The purple haired girl replied.

"Right! Come on in!"

A red light shifted to green before a click was heard, followed by the door opening.

Rarity gasped at first, taken aback by the sudden door opening. She cautiously stepped inside, looking around as she did so, though all she could see at first was complete darkness.

"Hello? Twilight are you there?" she spoke up.

There appeared to be no response at first, until a small light illuminated on a wall and shined down on her.

The fashionista shielded her eyes from the sudden light shining on her. "Twilight?" She called out, approaching the light closer. Upon closer inspection, Rarity saw what looked like a little screen on the wall. It fuzzed for a second, before Twilight's face appeared on it.

"Oh, hi there Rarity. I'm in the observation room right now," she said. "Hang on, I'll be down in a second."

The screen quickly snapped to black before the sound of a door opening is heard and Rarity could barely see Twilight climbing down a ladder and walking over to her until she was just a few feet away, now wearing a lab coat and looking more like a mad scientist.

"Hi! Welcome!" The geeky girl smiled.

Rarity pointed to the ladder, a little bit surprised. "Were you…. Up there?"

"Yup! I was working on something for Spike before you arrived." Twilight explained. "Anyway, ready to begin the tests?"

"As I'll ever…" Rarity replied, slowly.

The nerdy girl's eyes beamed with excitement. "Excellent! Let's get started then." She quickly pulled out a pen and notepad to write down results.

Next Chapter: Chapter 10 Estimated time remaining: 4 Hours, 32 Minutes