With the magic rushing through her, Rainbow Dash was barely working hard at all. She crouched down and shifted a little to the side to let Twilight off. When her passenger didn't move immediately, Rainbow Dash cleared her throat. "Uh, Twi? You can let go now."

Twilight Sparkle opened her eyes and almost squawked. She quickly climbed off Rainbow Dash's back and stood on her own wobbly legs again. "Do you always go that fast?"

"Sometimes faster. Usually faster. C'mon." As Rainbow Dash walked toward the Pie residence, she couldn't help but feel the strange way her hooves met the ground, and the stranger way her legs moved. Despite the strangeness of it, her legs worked well.

Walking beside Rainbow Dash, Twilight Sparkle was aware how different her friend was when ponied up. Normally, Rainbow Dash was the same height as Twilight was, but now she seemed smaller by half a foot. Twilight pulled out her phone and made note of her observation.

Rainbow Dash's finger almost made it to the doorbell button before the door opened. "Hi Pi—"

Answering the door, Pinkie Pie took a deep breath. "Thank goodness you're here! We thought she was just sleeping in but then Marble didn't get up all day and then we got worried about her and tried to wake her up and she doesn't wake up and this has to be the thing we were talking about and I don't know—" Pinkie was still talking, but with Sunset's hand over her mouth it was much more muffled.

"Come in, please." Sunset Shimmer guided Pinkie Pie from the doorway to let Rainbow Dash and Twilight Sparkle in. "You know which room's hers?"

"Yeah. I remember from the sleepover we had here." Rainbow Dash could pick up the vibe from Sunset that Pinkie Pie was in a panic. She gave Sunset a significant look, and got a nod in reply. "Come on, Twilight."

"You said that alread—" Feeling like a toy being hauled around, Twilight Sparkle realized the last few days with her brother had left her feeling "smaller." She braced and started walking with a more active stride. "Do you feel anything else that might be related? The sleep thing is worrying me."

Marble Pie's bedroom door was open. Inside the bedroom Marble Pie lay on her bed while Limestone Pie stood guard like a sentry. When she saw Rainbow Dash and Twilight Sparkle, Limestone gave a snort. "I get that this is something personal, but I think you should call a doctor. I've dealt with grunts who take a double hit of sleeping pills to get out of morning training before, but I could still wake them up."

Twilight looked from Marble to Limestone, then back again. "She just looks asleep. Let me check some things." Turning on her mobile phone's light, Twilight partly covered it with one hand while checking Marble's eye dilation with the other. "Her eyes are narrow, but when I shine some light she turns them away from it."

"What's that mean, brainiac?" Limestone, nonetheless, was relieved Twilight seemed to know what she was doing.

"She's not in a coma. Whatever is doing this to her, is doing it as sleep. Really deep sleep." Twilight Sparkle let Marble's eye close. She moved to test reflexes next, and eased one of Marble's legs out of the covers and used her phone to tap on Marble's patellar tendon. The weak reaction surprised Twilight. "But it's suppressing nervous activity. This is fascinating."

"Forget 'fascinating,' how do you fix this?" Holding back her anger, Limestone was still exceptionally confrontational.

Twilight looked to Rainbow, who shrugged. "Each case so far has resulted in the person waking up within two days. Pinkie said you tried to wake her?"

"Yeah, like this." Limestone had to gulp down her apprehension. She knew there was more to the world than you could see—magic—and this was just the kind of thing that scared her. She shoved her fear down and started gently shaking Marble's shoulder.

A horrible smell hit Rainbow Dash's nose. Taking a few steps out of the room, Rainbow could feel panic rising. "St-Stop! Don't do that." She didn't get any further words out before rushing for the bathroom.

"I'm not a doctor, not really close, but I can't think of anything this could be. I've already run some scans of Rainbow Dash, but could you send Marble to my place the moment she wakes up?" Twilight pulled out her phone again, and started a message with her home address on it. "What's your number?"

Grunting, Limestone reached into a pocket and pulled out her phone. Being on leave meant she might need to be contacted, so she had a mobile phone, not that she could remember the number. "Uh…" She read off the digits written on the back. The phone beeped—a message from Twilight.

"Send me a message the moment she wakes, and bring her around to my place when she can move." Twilight was typing her notes on Marble's condition into her phone.

Rainbow Dash, finished dealing with the bad feeling in her stomach with no casualties, poked her head around the doorjamb. "Uh, there's one problem with that. Remember the side effect? She might wake up, well—horny."

"No, you don't understand. It will start off as a light, uh, need." Rainbow Dash had the good grace to blush a little. "And it just gets worse and worse. She'll just need some alone time with, uh, something to help."

Twilight Sparkle could only stare at Rainbow Dash. Her mind was stuck—running in circles. All the options filled out as either sex with dog or masturbated kept her from opening her mouth lest she mention either of them.

"Soooo. I'm sure they've got things from here. House full of girls, they have some things to help her out, right?" Rainbow Dash looked at Limestone, only to see her looking clueless. "Ugh, come on. The girl'll need a vibrator when she wakes up. You can either send someone to…"

Rainbow Dash lifted one hand up to her forehead and closed her eyes. "Look. I'm going to see my boyfriend, who happens to work at a sex toy shop. I'll get something new and bring it back in the morning. How long has she been like this?"

Limestone stared at Rainbow Dash for a few seconds, not processing the question. Eventually her mind caught up. "Err, well, she was walking around yesterday afternoon. So I guess it could've hit her sometime since then."

Doing the math in her head, Rainbow Dash quickly figured out her safety margin. "Okay. I'll come around sometime around lunch tomorrow. If she wakes up before then—which she shouldn't—"

"I'm sure you do, Pinkie, but let's get her her own things." Making her way out of the room, Rainbow Dash reflected on how much she didn't want to be having this discussion with her friends. "Twilight? Do you need a lift home?"

Twilight's eyes suddenly went wide, memories of the ten second ride playing back in her head with full detail. "N-No! I mean, I can walk home if I need to, or call a taxi, or maybe get a ride from someone, or—"

"I'll drive you, Twilight." Sunset looked from Twilight to Rainbow Dash. "You're going to the meet up with the college people tomorrow?"

"Yeah, yeah. My parents are going to be freaked out, though." Rainbow Dash pulled up her phone and started a text.

—It cool if I come 2cu in 30?— Rainbow sent to Spicy.

"Bye everyone!" Leaving back through the front door, Rainbow Dash walked to the curb and spread her wings. She paused a moment and looked down at her hooves. "Well, I guess I should test these things out."

Bracing one hoof, Rainbow Dash leaned forward and left an actual dust cloud behind. Her legs moved even more effortlessly than usual, each new muscles straining in time to produce a more forceful gait than ever. It would have been faster to fly, Rainbow Dash estimated, but she was still home in mere seconds.

Unlocking the front door, Rainbow Dash saw Thunderbolt laying on the couch. While she watched, his big tail started to wag. "Yeah, yeah. I'm home and all that. Really worked up, too. You good for some fun?"

Thunderbolt yawned and nodded, but by then his mistress was looking away. As he'd practiced, he opened his mouth and made the noise. "Yus."

Rainbow Dash froze. She turned her head and looked at her dog—or at least the beast her dog had become. He was still Thunderbolt, but Rainbow could see more intelligence in his eyes than ever before. "Did you just speak?"

"Huh. Getting smarter, too." Rainbow Dash put patterns together. Her dog had been missing for a day or so, now he was horny all the time. But the capstone was his growing intelligence. "I guess whatever you're turning into is more clever than a dog. Good for you, boy."

Pulling her shirt over her head, Rainbow Dash started to pull at her shorts as she walked for her bedroom. "So I guess you got this itch-thing too. Lucky you have a horny little bitch here to—" Cutting short as her phone beeped, Rainbow Dash reached her room and kicked her panties and shorts off.

—Got it sorted.—

She was just pressing send when a long, hot, and raspy tongue ran up along her perineum and across her ass. In response, Rainbow Dash cocked her tail and leaned back into Thunderbolt's attention.

Thunderbolt knew his business and kept his tongue moving across Rainbow Dash's rump. He tasted old sweat and new, the salt tickling his taste buds as he lapped away at her fuzzy cleft. He jerked to a stop, however, when he heard her moan. Pulling back, Thunderbolt looked up to see Rainbow Dash had removed every piece of her clothing.

In Rainbow Dash's head, her own new hunger for sex drove all her thoughts. She was in control of the desires and needs of the parasite, it was fully part of her. Without knowing how or why, she turned on the floodgates for her own arousal and let out further moans of need as she assumed her position on the floor.

When Thunderbolt reared up onto her back, Rainbow Dash crouched a little lower for him. Her legs didn't have a knee as a human's should, but rather she could squat her new limbs down enough to put her at just the right height.

Thanks to Rainbow Dash unleashing a slew of chemicals into her own bloodstream, she was sopping wet and ready for Thunderbolt. One of his bulbous shaft-tips pressed at her entrance and, with a hefty shove from his rear leg muscles, was inside her.

Rainbow Dash could feel the second shaft grind under her, missing its target—she didn't care. The submissive side of Rainbow wallowed in the pleasure and romped with a loose rein. But unlike every other time, Thunderbolt didn't go wild with bucking.

Grabbing his bitch—when Rainbow Dash was under him, on him, she was his bitch—by the shoulders, Thunderbolt pulled her back onto one of his lengths. He could feel himself deep in her body—swelling. Bucking with his hips, Thunderbolt controlled every motion, every movement either of them made. He owned and possessed Rainbow Dash in a way his mind couldn't have comprehended just days before.

Pressing his neck against Rainbow Dash's back, Thunderbolt let out a satisfied growl. Inside his bitch he was swelling up, locking them together. It was different to how his body worked as a dog, but he didn't care—instincts were instincts, Thunderbolt only cared that he spent them on his prize bitch.

The sex was slower than she'd ever had with Thunderbolt before, but more intense at the same time. Every movement of him inside her, every action he forced her to take, drove the needy bitch in her head wild. Rainbow Dash squealed and whined, fully aware how perfect it was that her pet was learning to speak, while he drove the capability from her mind. She felt sharp teeth close around her neck, and while Thunderbolt took hold, Rainbow Dash climaxed.

Feeling his bitch peak, Thunderbolt felt this as a sure sign that something more vigorous was now needed. Shoving himself into her as deep as he could, using her shoulder and neck for leverage, Thunderbolt flapped his wings in excitement.

The anchor of Thunderbolt's hemipenis swelled up, the soft spines creating enough friction to lock it in place. His body trembled as the peak of copulation began.

Rainbow Dash's orgasm ran on and on. She couldn't move, couldn't struggle, could barely even think as Thunderbolt claimed her for himself. The swelling sensation was quickly augmented when a white-hot rush of liquid poured into her body. She squealed, screamed, moaned, and whined to her mate, but he wouldn't let go and wouldn't stop pumping his seed into her body.

Losing her will to struggle in the midst of orgasmic bliss, Rainbow Dash wallowed in the repeated, mini orgasms that flashed through her. Thunderbolt seemed to lean on her more heavily, bearing her down to her belly and eventually, to his side. Their bodies were still locked together, but now Rainbow was curled up under Thunderbolt's wing.

Thunderbolt began lapping at his bitch's neck. He could see pinpricks in her skin where his teeth had gripped, and admonished himself for almost hurting her. Again and again, as time slid by, his shaft would tingle and Thunderbolt would loose another rush into her.

Tied to her fate and her master, Rainbow Dash waited patiently for the swelling to recede. She loved the feel of Thunderbolt inside her body, but the repeated ejaculations were leaving her feeling extremely bloated.

It was over, Thunderbolt decided. He jerked his hips, tugging at the bulbous mass tying him to his bitch. Another jerk, then a third, and finally a fourth and he pulled free. When his bitch tried to crawl away to the cleaning room, he brought a heavy, clawed forelimb down on her back. Nuzzling under her tail, Thunderbolt began to lap at her folds.

Rainbow Dash stared ahead blindly. Her body was different than human now. Gone was the compact, hairless folds. She had a thick-lipped horse vulva, and Thunderbolt was treating it to the best licking she had ever felt. Her thoughts started slowly coming back to her while her reproductive tract started oozing out her lover's seed.

Licking until he couldn't taste himself on his bitch's nethers anymore, Thunderbolt nuzzled at her well-used entrance and gave a huff. "Good."

The word tickled the needy bitch in Rainbow's head right under the chin. She found herself making happy sounds, even as Thunderbolt's claws lifted from her back. Like a cat, Rainbow Dash slid to her hands and hooves and crawled to the bathroom to clean up.

Thunderbolt watched Rainbow Dash's rear disappear into the cleaning room. He yawned and rolled to his back. He didn't care that the other bitches of the neighborhood weren't big enough for him anymore, or that Rainbow Dash was his only partner now—it made these moments better.

Squirming on his back, Thunderbolt waited for Rainbow to leave the cleaning room to wiggle his hips.

Freezing in the bathroom doorway, Rainbow Dash stared at Thunderbolt's shafts. Both were limp—retracting back into his cloaca. She gulped, standing naked except for her wrist and neck cuffs. "Have fun?"

Tilting his head to the side, Thunderbolt pulled his lips into a smile—something he had seen Rainbow Dash do many times. "Yup."

Watching the expressive nature of Thunderbolt's altered face, Rainbow Dash decided to do something brash. Leaning down, she pressed her lips to Thunderbolt's. The kiss wasn't perfect, but she felt him shift a little in response to her soft touch. "I'll be back later, maybe in the morning. You cool with that?"

In Thunderbolt's mind, Rainbow Dash was on the floor again and he was covering her. Imagination serving to arouse him again, Thunderbolt nodded up to Rainbow Dash.

"Thanks." Rainbow Dash got dressed again quickly. Boxer shorts, running shorts, shirt, and a loose tie to keep her hair back. She grabbed her keys and wallet—pocketing both—and left her home.

Sexy Brain Parasite Story

by Damaged

A New Crisis Pt2