Relaxed, the pressure in her groin subsiding, Rainbow looked up at Rarity only to see her looking back. "Uh, Rarity?"
"Yes, Rainbow-dear?" A flick of her long lashes, and Rarity smiled at her friend.
"We—uh—We're good, right? About the things we talked about?" Rainbow Dash trailed a finger up to her throat.
"About that? We will talk about that tomorrow. About the other thing…" Slurping at her drink, Rarity smiled wide—the feeling of power was back, and it was as stimulating as ever. "The other thing is quite settled. You know what I expect of you, and I think you know what to expect of me?"
A little spring in Rainbow Dash's head coiled a little tighter. "Y-Y-Yes, Rarity." In truth she had no clue what to expect, except that Rarity would have control of a very intimate thing. A scheme formed, and Rainbow imagined trying to pretend she had the toy in her. She quickly threw it away, since she would never know what setting Rarity had put her on without having it in, and without knowing that she wouldn't know how to act.
Rainbow focused on her food, on her drink, in fact, she focused on anything but Rarity. Everyone was on such a high after their practice, that they all barely noticed when Mrs. Cake closed the front door and turned off half the lights. Pinkie and Sunset were the first to notice, and as the cute new couple slipped from the diner, Fluttershy, Twilight, and Applejack slipped off too. Rainbow Dash barely noticed that Rarity was the only other one there.
"Do we have something to talk about?" Rarity looked across the empty table at Rainbow Dash, but even with nothing else to look at, Rainbow still avoided her gaze. "Did I step out of line, Rainbow Dash?"
Her name, and the worried tone, surprised Rainbow. She looked up at Rarity. Her friend's voice echoed from earlier, commanding her to do things. Although Rainbow loved the idea of being told what to do, something wasn't right. "R-Rarity…" Rainbow stood up and walked around the end of the table as if her legs were stiff as boards. She halted beside Rarity, and then collapsed onto the chair.
Rarity was shocked as her friend collapsed in tears. She did the only thing she could think of, and put an arm around Rainbow Dash's shoulders and pulled her into a hug. "You're safe, darling. I didn't mean those things. We can stop and go back to normal now."
Pressing her face against Rarity's shoulder, all the stress and strangeness that had been building up was let loose in a gale-force rush of emotion. Rainbow just shook her head as Rarity whispered soft, comforting things to her. But soon, even her tears ran out, and Rarity slowed down her litany, and finally stopped that too.
Rainbow's emotions were raw. She opened her mouth and let her heart speak. "I'll wear it tomorrow, but please don't turn it on during class."
The shock of the words startled Rarity. She expected to be deleting the app from her phone, but what Rainbow Dash had just done was so far beyond that she almost needed to hear it twice. "You want to continue?"
"I-I liked it." Rainbow Dash couldn't believe what she was saying, but it was the absolute truth. "It was fun, and you sounded—you sounded in control." With a little shiver, Rainbow Dash hugged a little tighter against Rarity.
"Do you want it?" Rarity barely trusted her voice now. "Tell me."
"I want you to control my—my libido. But only outside of class. I still need to pass English and Geography."
Rarity chuckled at Rainbow Dash's reasoning. "We have a Geography test tomorrow morning, it was announced today. Your result will affect how good you feel during lunch." Rarity felt Rainbow stiffen beside her. Her voice turned worried. "Is that too much?"
"N-No. It's—It's perfect." Rainbow felt all her worry ease out and leave her. At least her annoying daytime arousal problem was now firmly under control—it just wasn't her control it was under. "Thank you, Rarity."
"You are welcome, dear." Rarity reached a hand up and stroked Rainbow's hair, running her digits through it, feeling how silky and smooth it was. They stayed cuddled together until Mrs. Cake finally had the heart to shoo them out.
Walking outside, Rarity was biting her lip anxiously. "R-Rainbow?" She looked at the girl who had seemed so fiercely independent, but now she could see the vulnerable parts of Rainbow, and everything in her wanted to protect them.
Lifting her head from her thoughts, Rainbow Dash looked at Rarity. "Y-Yes?"
"Just tell me to stop, and I will. I never want to hurt you again." The words came from the same place that embrace the magic within them. It was hot, emotion-filled, and it let those emotions out. "Ever."
"I promise, Rarity, that if it becomes too—too much, I will ask you to stop." Reaching one arm up, Rainbow Dash wiped the remnants of tears away from her eyes—badly. "I had better go home and study. What did they say the test would be on?"
"It will be on the south Pacific." Rarity watched Rainbow Dash climb onto her motorbike, and for a moment she couldn't fathom how Rainbow managed to sit astride it with something pushed up inside her. "And Rainbow?" There was something warming about how quickly Rainbow Dash's attention snapped to her. "The better you do, the more I will reward you."
Rainbow Dash was hot again. Turning the key on her bike, it felt like the vibrator was back on. The constant purring of the motorbike's engine seemed to echo up and down her body. Pushing the bike back a little and turning, Rainbow spared Rarity one more look before she kicked into gear and turned the throttle.
The ride was both nightmare and paradise. By the time Rainbow got home the pad in her underwear was soaked, and she was a giggling mess. Jumping off the bike, she turned the motor off and pulled the keys out. No sooner did she open the door from garage to house than Thunderbolt shoved his snout between her legs.
His bitch was back, and Thunder loved how worked up she smelled. Nuzzling around, he rolled his eyes up to look along Rainbow's body and to her blushing face. He pulled back and gave a bark.
Each time Rainbow's body got turned on, the parasite in her head took notes. It focused on what she was feeling, and what her reactions were. It had made a lot of notes about her interaction with Rarity, but as Rainbow gazed down at her dog, it registered the biggest hit to her libido so far.
Laughing, Rainbow tried to keep her speed low as she ran through the house. Her shirt was the first casualty, tossed carelessly into her laundry hamper as she entered her bedroom. Each garment landed in the same spot, until she was clad in her panties.
Even Rainbow Dash could smell her body now. The fluids filling the normally thin pad were puffing it up, and as Rainbow Dash bent down to pull the sticky underwear off, she felt a nose probing up from behind her. "Hold on!" Carefully, she eased the toy out from inside her, and carried it to the sink in her bathroom.
Horny as could be, Rainbow Dash made sure to clean her toy, but the insistent nosing of her pet kept her nerves dancing on edge. "Hold on!" Dancing on tiptoes, she made her way back into her bedroom and paused.
Urges and feelings surged in Rainbow. She knew she could just drop to her hands and knees and offer everything to Thunderbolt, but she still felt a little unsure about that. The floor, laying flat, seemed another good idea. Mulling over her option, Rainbow soon felt the first strike of Thunderbolt's tongue on her damp lips.
Instinct took hold, and although Rainbow didn't offer herself to her pet, she did lay down on the floor and part her legs. Rolling to the back, her pet was in place before Rainbow even settled.
Pressing one paw on his bitch's belly, Thunderbolt started licking. Excitement—mostly hers—stirred him to go faster, and he soon heard Rainbow Dash moaning and squirming. There was something missing, something special his bitch had done for him the last time they had been together.
Rainbow Dash watched as Thunderbolt casually turned to his side and lifted his upper, back leg. He wasn't even hard, only the barest tip was poking from Thunderbolt's sheath, but Rainbow reached for him, and kissed the hot flesh that Thunder was offering her.
The licking suddenly grew more intense, and Rainbow Dash got into her groove. Thunderbolt swelled into her mouth, and she reached up to grip him tightly around the knot with her hand.
Though the parasite felt Rainbow Dash feeding it yet again, it could taste the pheromones its twin within Thunderbolt put out. It's twin wasn't as well developed as it was, but the limited capacity of Thunderbolt's brain meant it would not take as long to fill his head.
Both Rainbow and Thunderbolt fought off their rising pleasure, wanting to extend the simple acts of getting and giving pleasure, but it wasn't to last. Rainbow tensed up, and though she kept her hand in place to stop her pet shoving all the way into her mouth again, part of her wanted him all. Gulping for all she was worth, Rainbow took every drop Thunderbolt had for her.
The parasite in Rainbow's head rewarded its host, always giving her a rush of extra pleasure for the simple act of feeding it. It had been building up to something, and tonight it would carry out its first laying. It expected its host to go to sleep immediately, but instead Rainbow Dash slipped out of her bedroom, away from her canine lover, and took to the computer.
It had no notion of study, or geography, but the parasite's host did. It sensed that Rainbow was trying to memorize and record complex patterns, and although it couldn't control the girl's own white matter yet, it could relegate some of its own to her use.
It sensed that she was still trying to focus, despite a rush of melatonin in her own brain. The raw chemistry of her brain was well within the framework of the parasite's control, and wanting to help its host, the parasite blocked the chemical.
"Whoa…" Rainbow Dash stared, in awe, at the time on the clock. "Tired or not, I need to sleep. This has been the most amazing study session ever!" Standing up, she sauntered back to her bedroom. Each step seemed harder and harder. Rainbow felt her pineal gland go into overload flooding her with melatonin. By the time she reached her bed she was barely awake, and slumping under the covers, she let the sweet oblivion of rest take over.
But Rainbow Dash's night was not finished. The parasite forced more melatonin, and a small cocktail of other drugs into her brain. The core part of Rainbow Dash's mind sank into a deep, dreamless sleep.
The first days of its stay, the parasite had been forced to work Rainbow Dash's limbs completely manually. The process had been a learning curve that had been made easier by its recent interfacing with the higher functions in Rainbow's head.
Crawling from bed, Rainbow Dash made her slow way across the floor of her bedroom stark naked. Though it was Rainbow's body, the girl was not at the wheel, and her limbs flopped more than moved gracefully. Slowly, she made it not only to her back door, but she slipped lithely through the doggy door.
Weight landed on Rainbow's back, and the parasite quickly tried to assess what it was. Turning her head, it read information from Rainbow's visual center, and identified Thunderbolt. Dreams were all the parasite had to go on. Rainbow's daydreams of what she had wanted to do with her pet. Pushing backwards with her arms, the parasite pushed its host's rear into the air.
Thunderbolt needed no further urging. Jumping up again, landing on his bitch's back, he shoved and pushed forward, and like the previous time he had no luck at first. Suddenly, though, his bitch finally, truly, became his. Thunderbolt sank into Rainbow Dash, and like the animal he was he leapt into action.
Rainbow's body, led by the parasite's urgings, started rocking with the hard thrusts from Thunderbolt. No sound came from her mouth, but every part of her felt the hot pleasure of Thunderbolt's penetration, of the most primal and hard-wired of happiness: sex.
Pressure grew inside Rainbow Dash as Thunderbolt serviced her. In her passage, the dogs knot was swelling up larger and larger. Eventually, even Thunderbolt's jerking hips couldn't separate him from her, and the pair were tied.
Growling and humping as hard and fast as he could, Thunderbolt's mind flooded with a rush of chemicals as he plowed his seed into his bitch. His body was like a hose, and each movement caused another flood of hot seed to splash into her. When his own pleasure died down, Thunderbolt stood up and tried to leave his bitch.
The knot was a quick reminder that Thunderbolt's body was not done with his bitch yet. Turning, he lay down behind Rainbow to await the tie to break.
Time passed as both dog and bitch waited for the knot to deflate. The parasite was not patient, however, and kept rocking Rainbow's hips to test the tie. Eventually, a stretching feeling told it that its latest efforts could be successful, and it rocked harder. Thick, sloppy dog seed leaked from Rainbow's folds. Finding its feast complete, the parasite continued its crawling.
In Rainbow's head, the parasite was not only basking in food, but it was giving something back to its host. Flooding Rainbow Dash's bloodstream (along with the hormones of sexual release) was a torrent of foreign eggs. Her body didn't trigger an immune response to them, as the parasite had coated each with the same careful blend of chemicals that protected it from her body.
The minuscule eggs, each propelled by a tiny tail, had a rudimentary sensing organ on the front. It was a complex contraption, so far as unprotected eggs usually went, but it was built to bring the eggs to some very particular places in the body.
Slipping through a hole in the fence, the parasite crawled Rainbow Dash down the the river that ran behind her home. The river was slow-moving, which was just what the parasite wanted. As Rainbow's body turned around, the eggs inside her were directing themselves to her bladder and her womb. With their energetic tails, and tiny size, the eggs passed into her womb and bladder.
The parasite felt one of the most rudimentary processes of any complex creature start to happen, and it achieved a level of happiness that even Rainbow Dash and Thunderbolt might never know. As Rainbow's body voided what it thought was waste, a torrent of the parasite's eggs flooded out into the water.