Sexy Brain Parasite Story

by Damaged


The Herd Grows

"Hey boy." Clad in a skirt and shorts, Rainbow had none of the problems from the last time she had seen her pet. Crouching down, she ruffled at his head. "Sorry about last time. You just startled me so much, and I totally should have expected you to investigate that smell."

Rainbow Dash's apology earned her a lick up one cheek from the big dog.

"You're the best, Thunderbolt." With her spirits lifted, Rainbow Dash stood up straight, only to feel a bit of a head-rush. The lack of arousal meant she noticed all the little flu symptoms that an immune system at war with, say, a brain parasite, would give. "As Twilight would say, I need a list."

Opening the door and letting Thunderbolt into the house, Rainbow made her way to the second bedroom—that she had turned into a study. It wasn't a room often frequented by Rainbow, but it wasn't neglected either. Dropping into her computer chair, she turned on her PC and pulled out her notepad and started writing.

Getting horny a lot
—multiple times a day (3-4)
—really distracting
—anticipate?
Ponying up more than normal
—music makes it really awesome
—when I get horny
—when I ride my bike

She tapped her pen, and then added under the Getting Horny a Lot heading, "Multiple orgasms are awesome too," and made sure to underline it a few times. "So how am I going to deal with this Thund—" Turning to her pet as she spoke, Rainbow was frozen for a moment as she watched her faithful shepherd licking a bright red spike of flesh.

Turning back to the computer slowly, Rainbow's fingers moved on their own. She searched for "Adult Toys." Words were her only reply from the internet, until she clicked on image search. Rainbow's heart beat faster, and she could see all kinds of shapes and pointy things. "Wow, there are a lot…"

As she scrolled, she saw a lot of the pics in one grouping were from the same website: Canterlot Circle. This time she searched for the place by name, and found out that there was a sex toy store in Canterlot. She moused over "Vibrators" and clicked.

With an extreme force of will, and about twenty minutes, Rainbow Dash managed to stop ogling the toys. A look at the site, however, revealed there was no way to order things online. "I am going to have to go in…"

Pulling the notepad over again, Rainbow started off strong. She scribbled things down, double-spacing her plan so that she could add things into the gaps, and all too soon had nearly a full page.

The Plan
Go back to school and see the school nurse
Get tomorrow off
Go to music practice, DON'T SING
—Hey, why not let Fluttershy?
Ride bike home
—CAREFULLY
Relieve self before bed
Relieve self in morning
Ride to store
Buy a toy to use during lunch break
"Test it"
Victory

"Princess Twi would be so proud of me!" A silly laugh caught her, and Rainbow's thoughts turned to her pony princess friend. A rush of warmth accompanied the image of Twilight, with her hair down, leaning over her. "No! Twilight is not sexy!" Shaking her head, Rainbow Dash turned off the screen on her computer, grabbed The Plan, and turned around.

"Alright boy, you can stay inside while I get this done. You know the rules, no parties, no girls over, and don't make a mess." Rainbow's higher spirits at knowing what she was going to do paid dividends. Practically bouncing along, she found her bag in the garage, but of course no bike.

Remembering back to the blond-haired goddess who had saved her butt, Rainbow couldn't hold a grudge. "Alright, I made this in ten seconds flat last time…" Securing her bag to her back, Rainbow pulled her phone out of her bag—ignoring the messages flashing on it for the moment—and started the timer.

Nine seconds later Rainbow Dash touched the corner of the school building closest to her house. Not even panting, she rolled her shoulders. Remembering what it had been like to fly at Camp Everfree, she pulled out her list and added a note at the bottom, "Practice with wings."

Walking up to the main doors of the school, Rainbow checked the time and saw that the last period of the day was just getting into gear. Coughing a few times, she ponied down just as she reached the nurse's office. "Nurse Redheart?"

"Rainbow Dash?" Nurse Redheart was astounded to see the school's number one athlete. "I heard you were sick earlier, Derpy came and told me she gave you a ride home on your bike. I had to give the poor dear a pass for her shop class."

"Yeah, about that." The cough picked the perfect moment to come back, and Rainbow Dash lifted her hand to cover her mouth. "S-Sorry about that. I must have caught something while I was at camp." She waved a hand in the vague direction of Camp Everfree.

"It certainly sounds like it. No school for two days, I don't want to see an outbreak of this." Redheart was already scribbling a sick pass for the girl. "And rest that voice of yours, I don't want Principal Celestia breathing down my neck over why your band isn't headlining for the varsity game next week."

"V-V-Varsity? What do you mean?" Rainbow's eyes focused down to pin pricks. "C-C-College? We have a gig?" She had ponied up again, and was practically bouncing in place with excitement.

Redheart blushed a little, but couldn't help but get enthused at the Rainbow Dash's display of pure giddy happiness. "I… might have ruined Principal Celestia's surprise, but yes. So rest your voice."

Rainbow Dash practically launched herself out of the nurse's office, and set up for a run. She got three seconds down the hall and had to slam on the brakes. Stepping back a few paces, she looked through a door into a classroom.

At the front of the class, Derpy was paying close attention to her notebook. Unfortunately she was drawing in it, when she should have been taking notes. Glancing up, she saw Rainbow Dash in the doorway, and smiled at the girl.

A thumbs up, and a smile, and Rainbow was gone again before the teacher could turn and see her. Slowing up as she left the back of the school building, Rainbow Dash looked around for her bike. Sure enough, Derpy had parked it back in her usual spot. "I am going to have to do something awesome for Derpy…" No sooner did the thought cross her mind, than Rainbow pictured herself licking between Derpy's Hooves' legs.

Rainbow rocked in place, her mind tripping over the scene in her head for nearly a minute before she gasped for breath. "Whoa! Nope, not that again. I am going up to the music room and I am going to practice, not masturbate."

Finding her bike locked up, Rainbow Dash made her way back into the school and up to the second floor music room. There was no class in it, and she let herself in. In a bit of a daze from the continued fantasies about Derpy—not that Rainbow was into girls, but apparently she might be… just a little—she grabbed her guitar out, walked over to the little stage and plugged up an amplifier.

With a double check to make sure the amp was down low, she began to play chords. Strumming up and down, her fingers moved slowly at first. Rainbow's mind cleared of everything else, and she fell into a song without realizing it. Power chords rattled through her fingers, and a shiver ran through her. Still ponied up from the news from Nurse Redheart, she barely noticed when the magic powered her up more. A flowing, rainbow colored tail sprouted from the girl's rear, and her hair seemed to spring up a little, growing wildly out of control.

Time seemed to have no meaning, and Rainbow didn't even realize the bell had rung until the door of the music room opened and six other girls filed in. "Hey guys, I—"

"I told you not to play!" Sunset smacked herself in the forehead with her hand. "Rainbow Dash, this could have been really dangerous!"

"Could have been?" Twilight Sparkle, genius and friend, looked from Rainbow's oddly more-pony-like form to Sunset. "You said you were waiting for us all to get together to tell us something. Does this have to do with it?" She gestured to Rainbow Dash.

Fluttershy, however, was completely ignoring the others. She gazed at Rainbow Dash in awe. Emitting a high-pitched squeal of excitement, she raced over to Rainbow. "Oh my gosh. This looks so cute! Look at your tail! Oh, I need to brush it!"

All eyes were on Fluttershy, although the moment the girl started to brush her tail, Rainbow Dash closed her eyelids and almost purred. Relaxation hit her like the softest hammer ever. "F-F-Fluttershy…" Words failed to come out, and then failed to even go together in her head.

"When we practiced before school today, we both ponied up like that." Sunset pointed to Rainbow Dash, who looked completely blissed out at the attention. "I told Rainbow to avoid playing until I heard back from Princess Twilight about it."

"And what did Her Royal Highness, Princess Twilight Sparkle of Equestria, say?" Rarity couldn't help using her friend's—her personal friend's—full title. It was hard to get over having actual royalty as a friend, at least for someone so focused on social standing.

"She was a bit busy, something about someone mind-controlling all her friends…" Sunset rolled her eyes. While she hoped Twilight had been joking, she knew Equestria well enough that it probably wasn't a joke at all. "But she said that it would be natural for there to be more magic here. By using our powers we drag more Equestrian magic into our world."

Rainbow shook her head to clear the soft fuzz that Fluttershy's brushing introduced, and jumped back into the conversation. "Wait, so why were you just yelling at me?"

"Well…" Realizing she might have been in the wrong, in an odd way, Sunset did what she had learned to do from the literal Princess of Friendship. "Sorry Rainbow Dash." She held out her hand to her friend.

"I could never stay angry at someone who plays as well as you." Rainbow grabbed the offered hand and used it to pull herself up and hug Sunset. "You were only doing it because you were worried for me, after all. But hey, if Princess Twilight says it's cool, let's rock!"

"Weren't we going to do one of Fluttershy's new songs tonight?" Sunset had avoided touching Rainbow with her hands, and definitely hadn't pushed her special power into gear. But the hug had made her feel much better. Friendship was, as Princess Twilight always said, magic.

"Oh crap!" Rainbow Dash felt panic strike. "I didn't get a copy of the lyrics during geography, sorry, Fluttershy. I am not meant to sing, either…"

"Darling, what's the matter?" Rarity practically hovered closer to Rainbow, offering her a pure white handkerchief.

"Just the flu. Sore throat, runny nose. Thanks Rarity." Taking the square of cloth, Rainbow Dash lifted it up to her nose and blew hard. It sounded like a foghorn, and the noise echoed around the room despite the deadening baffles on some sections of wall. "But that's alright, Fluttershy can sing it. It's her song, after all."

Fluttershy's eyes narrowed down, her pupils shrunk, and she shook her head. "Oh! No, no, no!" Though she shouted the words, they barely came past her lips. "I couldn't possibly sing this, it is far too noisy and loud, and I just want to play my tambourine and…"

"Fluttershy. It will only be us here. No one else will see you singing." Pinkie Pie took her friend's hands in her own and held them up. "You are the only one here who knows the words."

With her heart pounding in her chest, Fluttershy looked between each of her friends one by one. She was only halfway through when she reached Rainbow Dash, and a surge of confidence hit her. The urge to start brushing her friend's tail almost overwhelmed her, so much so that she wasn't even sure what was happening when she opened her mouth. "Okay…"

Rainbow was still plugged in, which gave her a moment to look over the lead guitar part. "Whoa, this looks awesome, Fluttershy. But we are going to have to go up to a minor key. Your voice will do better coming in on top of that." Her fingers started to strum, and the main riff of the song poured like honey from her amplifier.

Pinkie Pie was first in after Rainbow, her drum-kit was already set up, all she had to do was jump over them, land on her seat, and her sticks fell in line with Rainbow Dash's playing.

Applejack's bass came in, then Rarity's keytar. Sunset's rhythm supported Rainbow Dash, showing the flair the blue-skinned girl put through her instrument. Twilight slipped in behind the mix desk, her magic manipulating dozens of controls at once, blending the different instruments perfectly.

Closing her eyes, Fluttershy lifted the mic up to her lips and sighed into it. "When my friends are by my side, when everyone's ready to go, I feel a swelling in my spirit, I feel my heart start to glow!" She felt as her body changed, it was so much more than normal that she couldn't ignore it. She missed a bar, and rather than come in late, she waited for the rhythm to come around again. "I stretch my wings, I lift up high! I shoot to the skyyyyy!"

Rainbow was already in love with the song, and something about focusing on her guitar work inspired her even more than normal. The power of the music, of friendship, rushed through her. Her fingers were like greased lightning on the neck of the guitar, and she heard a double slap come from Applejack's bass that signaled a quick change of key. Down into a major, she opened her mouth to sing backing for Fluttershy's next line—she wasn't sure how she knew it would need backing, it just felt right.

At that moment, the door to the music room opened, and Vice-Principal Luna slipped in. She perked up at the sound of the talented teens playing, and practically slumped back against the door as the music seeped into her heart. She was startled, suddenly, when it cut off. "Oh! S-Sorry for interrupting. Principal Celestia wanted to come down herself, but she had Snips and Snails for detention… again."

"Uh…" Rainbow Dash, like her friends, couldn't stop staring at Luna. Their eyes were glued to the woman. "You… uh… S-Sunset, back me up."

But before Sunset could say anything, Twilight flexed her magic—that she had been practicing whenever possible—and floated a mirror before the Vice-Principal.

Luna didn't notice at first, but once she did it was impossible to look away. A pair of blue, fuzzy ears stood atop her head. They perked forward in apparent excitement. Her hair stretched long down her back, and in the angle of the mirror she could see it trailed behind her a little too. And of course, at her shoulders, a pair of cobalt blue wings were spread out. "W-W-What… What is this?"

Sporting her mane, ears, tail, and wings; Rainbow Dash walked up to Luna, but turned back to Sunset. "Uh, did Princess Twilight say anything about this? I mean, I knew we were good, but this is awesome!"

Reaching a hand up to the top of her head, Luna felt one of her ears, felt it try to tuck back under her touch. "Y-Y-You…" She cleared her throat and tried to regain her calm. "Youhavebeenaskedtoplayatnextweek'svarsityfootballgame!" Turning, Luna pulled open the door and ran from the girls, from the music room, and from the music that had changed her. Her heart thudded, and her mouth was dry, but when she ducked into the first empty classroom she could, she held up the mirror again to look at her ears.

"Real magic. They put some of their magic in… in me!" Giggling like a schoolgirl, Luna gave a squee of excitement. "I'm a pony girl too!"