Spike sighed as he slipped out of his bed, landing his feet on the surprisingly warm crystalline floor. This was easily his least favorite part of the day since it led to the rest of his surreal day. He looked around the dark room, his vision being brought to the bright red digital text on his alarm clock, reading 6:45. He took a quick shower before donning a baggy pair of jeans, a light purple t-shirt and walking out to the Crystal Castle kitchen.

"Twilight! Time to wake up!" Spike shouted as he passed Twilight's room and continued his walk to the kitchen. Once he reached the surprisingly spacious kitchen, he took a few slices of bacon and a few eggs, preparing the frying pan and cooking up the meat and unborn chicken embryos. Now that Spike thought about eggs that way he decided he wasn't that hungry for them. After checking the mail, preparing the table and putting the finishing touches on his and Twilight's breakfast, Twilight finally came downstairs. Spike was putting the dirty frying pan in the sink to soak as he heard Twilight yawn and tread dainty footsteps across the floor.

"Morning, Twi. There was something in the mail that said- Gah!" Spike exclaimed as he turned around to reveal his adoptive sister wearing a fluffy light purple bathrobe that seemed to be made for a child rather than a 25-year-old woman. The robe only just covered her shaven vulva but left the bottoms of her butt cheeks visible and her large breasts could not be completely covered by the small gown, leaving her hard and perky nipples in the open air for Spike to see. Twilight looked at her adopted brother with a look of confusion.

"Like, what's wrong, Spike?" Twilight asked, her eyebrow raised and her large lips slightly parted. She was oblivious to her breast slipping out further as she moved her arms to pick up her knife and fork, making her smooth boobs bounce out of the gown to become fully exposed as she tucked into her meal.

"Twilight! Could you at least were some underwear in the house?" Spike asked, directing his attention away from Twilight's mammaries rising and falling as she took in breaths.

"Why? It's my castle, my rules. You just be happy you get to where clothes in here mister." Twilight giggled as she looked up at her blushing brother. Spike didn't know why he was bothered by Twilight's loose feeling on clothing, this must have been the third time this week she came down in incredibly revealing clothing. Spike smiled as he reminisced the old days in Canterlot where Twilight was a completely normal, if anti-social, woman. Spike never bothered to ask why, but one side effect of using the Elements of Harmony was a physical and psychological transformation. When Twilight arrived in Ponyville she had a fairly unimpressive pair of B-cup breasts, 30" waist, and hips, a height of 5' 5" and a chubby body.

But after using the Elements to defeat Nightmare Moon, her body slowly transformed. It was slow at first, her body gradually losing some of it's weight and getting more toned, her breasts growing in size and getting rounded into a small D-cup, her hips widening to 34", her waist shrinking to 28" and her height rising to 5' 11". Her brain was also affected by the Elements, still maintaining her incredible intelligence and knowledge but losing some of her common sense and becoming altogether more scatter-brained. She also became a lot more interested in boys that she had been before by going on multiple dates every month and finally losing her virginity.

However, after the Elements second use against Discord, they increased the transformations speed and force upon her mind and body. After Discord was encased in his stone prison, Twilight's already sized-up D-cup grew to an even bigger DD-cup, her hips grew to a wider 39" and she grew a little bit taller at about 6' 5". Of course, her brain was once again affected, losing the ability to understand more elaborate jokes and getting distracted surprisingly easily. She wasn't exactly dumb, just a bit air-headed. She could discuss Star Swirl The Bearded's research into differential magic wave theory but at the same time couldn't remember where she had left her keys, only to find them sitting in her lavishly expensive and 'cute' purse. Her sex-drive had also increased immensely, seemingly going on a new date every week and bedding multiple men every month. Sometimes she would even send Spike to his room early like an angry mother while her friends came to the castle and go to Twilight's room to do... Something. Spike didn't put much thought into what was happening, and asking Twilight would only lead to her teasing him further and further.

"That's not the point... I-I'm you... I'm your brother." Spike said, looking down at his plate as Twilight rolled her eyes, produced an audible 'hmph' and fixed her robe to cover her breasts.

"Hehehe, not by blood!" Twilight giggled, giving Spike a cheeky smirk as she dug into her meal, talking to Spike about the debaucherous dream she had last night, her plans for the day, what chores Spike had, her date for the night and her plans to go to the mall on Saturday with her friends. When the siblings were finished with their food, they went their separate ways to complete their respective tasks, Twilight helping Rarity at her boutique and Spike cleaning the castle's library.

Spike scrubbed the tough grease off of the frying pan, wiping the sweat from his brow as he continued to coax the stubborn grime of the pan. After finally getting the final patch of dirt from the frying pan he placed it out to dry and walked into the Castle's spacious living room, flopped himself down on the couch, switched the TV on, found a vintage horror movie and chilled out with a pack of chips. After a few minutes of watching the movie and munching on his chips, Spike heard a loud slam come from the Castle entrance.

"Stupid, selfish pig!" He heard a voice shout from the hallway. I wonder how Twilight's date went? Spike thought sarcastically, getting up from his seated position and walking into the hallway. Twilight was standing near the entrance, her head against the wall, standing perfectly still, Spike walked up to her and couldn't help but notice what she was wearing. A small, almost black shade of purple cocktail dress hugged her toned body and highlighted her curves perfectly. Her boobs almost spilled out of the cleavage space as Spike noticed she was wearing some frilly lingerie for her date. Spike could tell Twilight had actually made an effort this time when compared to some of her previous dates, not going with the ever popular super short miniskirt and tight dress shirt she usually wore. A plethora of dates gone wrong had caused her to change her attitudes and dress code, but Spike could tell she was still looking to score. And hard.

"Twilight... You okay?" Spike asked his gloomy sister. Twilight kept her head rested on the wall as she sighed.

"No..." Twilight sighed after a few seconds, keeping her forehead rested on the wall.

"Y'wanna talk about it?" Spike asked, placing a caring hand on her shoulder, making her smile a little bit more.

"Yeah..." Twilight sighed.

"What happened?" Spike asked, giving her a hug from behind.

"The guy was a total dick. Like, I know sometimes I just wanna fuck, but... Sometimes a wanna little something more, y'know." Twilight hypothetically asked her young assistant, placing a hand on his as it rested on her toned stomach. Spike cringed as Twilight revealed a detail he really didn't want to hear but tightened his grip around the girl's waist.

"What did he do?" Spike asked, keeping interest in Twilight's night.

"He totally treated me like a whore, gosh! Some men are such dicks. I thought he was nice... He just wanted my body." Twilight sighed, clearly unhappy with how her night went.

"Did you teach him a lesson?" Spike asked, playfully.

"Let's just say, like, he won't be using any woman's body in a while." Twilight giggled as she remembered the tip of her high heel connecting with his nutsack. Spike shared a laugh with her as he rubbed her toned belly. Spike wasn't happy with being this physically intimate with his sister, but she was clearly having a bad time and Spike knew she loved hugs with her brother.

"Do you want anything?" Spike asked, disconnecting with Twilight as he gently pulled her from her resting place.

"Nah..." Twilight huffed.

"Do you wanna watch some TV with me?" Spike asked, gently guiding Twilight down the hall as she lazily plodded along the crystal floor, her high-heels clicking and clacking against the surface.

"Nah... Thanks a bunch, though. Why can't more guys be like you?" She asked, smiling down at her younger brother.

"I'm sure someone's perfect for you. If you need anything from me, I'll be down here." Spike chuckled.

"Yeah... Goodnight" Twilight sighed, disconnecting from him and kissing him on the forehead, leaving a purple lipstick mark and a blushing set of cheeks. Twilight walked away from Spike, treading up the stairs to her room, her breasts and ass jiggling as she did. Spike went back to the living room and continued with his movie.

"Anything, huh?" Twilight asked no one, smiling seductively.

The loud, guttural sounds of Spike's snores echoed through the spacious environment of the Castle lounge. He had fallen asleep a while ago, his sleeping body illuminated by the infomercials that were playing on the active TV. Spike did not wake when bare footsteps patted across the ground, inching closer and closer to him. Twilight was only wearing the robe she had worn in the morning, her breasts bouncing out of the small gown as she walked over to the sleeping Spike. She knelt down in front of him, slowly spreading his legs and fitting snugly between them. She very slowly rubbed up and down his muscular thighs, getting closer and closer to his crotch with every stroke.

"I need this Spike. I'm sure you'd understand." Twilight whispered, brushing her hand over Spike's flaccid cock beneath the thick denim. She snaked her hand up further to the metal of his jean button, unbuttoning it and slowly pulling his jeans and boxers down and revealing his flaccid cock. Twilight gasped as the limp dick flopped out of cloth prison to create an audible 'whap'. It wasn't even erect and it was a fair 11" and a width of about 2.5", Twilight knew Spike had a pretty big growth spurt before his 18th Birthday a few days ago, but she wasn't expecting this! Twilight could work with this dick flaccid, her nethers burned as she imagined what she could do with it when erect.

"It is true what they say about Dragon-Bloods!" Twilight gasped as she studied his cock. The head was a light purplish hue with a tight slit, the shaft was fleshy with a few thick veins traveling up the pole of meat and his balls were large, round and so low they rested on the couch cushion. Twilight licked her lips as she hungrily eyed the soft cock up and down. She couldn't stop herself as she lunged on Spike's cock, giving it a long, snaking lick from tip to base, moaning as the familiar taste of sexual flesh danced across her taste-buds. After a few more licks and kisses, Spike's virgin cock was at full, very impressive, mast. His cock looked painfully hard, throbbing as his body pumped blood into the full and frankly gargantuan thirteen inches long and three and a half inches wide of man meat. Twilight whimpered as the cock flopped against Spike's belly and throbbed powerfully, releasing a small spurt of thick, cloudy pre-cum onto Spike's shirt.

"Oh. My. Fucking. Celestia. I think I just came." Twilight whispered to herself, simply staring and admiring her new favorite cock in the whole world. She imagined the cock impaling her pussy over and over again, making her cum until she passed out and then fucking her still until she woke up to repeat the whole process again. She imagined Spike pushing her onto her knees to aim his cannon at her needy face and tits, jerking the shaft until cum rocketed out of the tip and covered her in the thick cream from his balls until she was caked in her brother's jism.

Twilight was suddenly struck with a naughty idea that could help her in some future endeavors. She grabbed her discarded robe and reached into her pocket, grabbing her sleek, little smartphone. She opened her camera app and switched the lens to the front-facing option before holding it at arm's length. She ducked her head so it was nuzzling the large pole of meat and snapped the picture, saving her new favorite photo onto her phone. As she put her phone back into her pocket her mind continued to wonder about what she could do with the powerful cock in front of her.

But Twilight's mind wasn't one for imaging, it was a mind made for doing. She placed both of her hands on the perfect cock and slowly pulled it towards her until it tumbled towards her, flicking a few beads of pre onto Twilight's collarbone as it hung in front of her face. She pushed the heavy cock up and began to stroke the shaft adoringly, quivering as she watched more beads of cloudy pre-cum run down from Spike's head. She placed her tongue on the underside of his thick shaft, dragging it up to the head, tasting the salty and tantalizing pre. She continued licking and stroking the shaft with one hand and rolling his large and hefty testicles with the other. Eventually, she placed her cushy lips on Spike's tip, a purple lipstick mark marking his shining helmet before she slid her mouth further down his cock to about halfway down until she began to feel resistance poking at the back of her throat. She didn't want to waste any time, Spike could wake up at any moment and this would be very difficult to the young teen. She kept her head there, licking up the thick shaft and tightening her cheeks, causing Spike to moan in his sleep. Twilight bobbed her head up and down Spike's shaft, occasionally taking her head off his cock to tenderly lick and suck his beautiful balls, taking in the thick, sour scent of his powerful dragon musk.

Twilight's blowjob made Spike moan louder and louder, eventually stirring him awake. Spike slowly pried his eyes open, looking around the room as he was taken from his slumber by unknown pleasure. He looked forward, coming face to face with his adoptive sister pampering his cock with her mouth.

"What the fuck!? Twilight!?" Spike shouted, backing up and popping his cock out of her mouth, a string of her saliva connecting her vacant lips with his rock hard dick.

"Oh my gawsh! Sorry, Spike! I didn't think you'd wake up." Twilight said, placing her hands back on Spike's slick, purple lipstick covered cock.

"That doesn't... That isn't... What!?" Spike shouted, clearly confused by the transpiring events.

"You's said, like, if you need anything, you'd be there." Twilight said, placing a light and cute peck on the tip of Spike's throbbing, glistening cock while her eyes beamed a sickly sweet 'sowwy' at him.

"I didn't mean this!?" Spike said, backing up the sofa more.

"Aww come on, Spike. I hadn't had a cock in, like, forever!" Twilight pleaded, giving Spike the puppy-dog-eyes and squeezing her tits together, a move that she had mastered in her time of being a bimbo.

"Uhhh... Ok, I guess." Spike said, relaxing a little more as Twilight ran her dainty hands up Spike's cock. Twilight had gotten him very worked up with her expert blowjob skills, he was desperate for release, even if it was his sister giving it to him. And the teasing she had started in the last few weeks was enough to make him jerk his cock alone every single night, even if she knew it was wrong.

"Yeah!" Twilight yelled, triumphantly pumping her fist in the air. She quickly went about lathering up Spike's cock with her saliva, covering it with her own brand of nasty lube. When she was happy that his cock was perfectly lubed, she took her large knockers and placed them around Spike's member, moving them up and down slowly. Spike wasn't conscious for most of Twilight's blowjob, but her titjob was bringing him closer to orgasm as the soft flesh of her tits squeezed around his shaft and the combination of Twilight's saliva and his pre-cum made the perfect lube for tit-fucking.

"Who would've thought my baby brother has the biggest cock in town?" Twilight breathed seductively, giving Spike a half-lidded expression as she leaned down and started licking and sucking on the head, maintaining burning eye contact with her brother.

Spike could only groan in response as he threw his head back in pleasure, bucking his hips upward in a desperate attempt to get to his orgasm. Twilight giggled as she watched Spike's blushing face contort as the new form of pleasure changed his mind. He had jerked off before, but this was something completely different. Twilight's tit's wrapped tightly around his cock, her lips smacking against the head of his long dick as she guided her soft titties down his fat pole, the smallest moans and whimpers she let out as Spike's pre-cum covered her slutty lips and the way she looked at him with a smoldering pleasured gaze, as if she was getting as much pleasure from him as he was from her.

"Is this your first time... With a girl?" Twilight giggled, smiling warmly at her adopted brother as Spike was now thrusting into her tits on his own accord, holding onto the cushions of the couch for dear life.

"Uhhh... Yeah..." Spike groaned as he felt his powerful orgasm building higher and higher.

"OMG! I can't believe I'm the first to handle your huge dick. I bet you didn't think your sister would be your first? I bet you've got a big load saved up in those big balls, all for your big sister, huh?"

"Ohhh... Fuck, Twilight... I'm close." Spike groaned as he furiously humped Twilight's breasts, making obscene sounds of wet flesh slapping against wet flesh while Twilight moaned and squeaked his name.

"Cum for me, baby brother. Cover your slut sister like you've always wanted to." Twilight whispered as she took her tits off Spike's cock, replacing the globes of fat with her hot, wet mouth. Spike bucked his hips upwards, making Twilight gag as she felt Spike's cock hit the back of her throat. She wrapped her dainty hand around the remainder of Spike's shaft, giving him fast, tight twists and tickling his dickhead and glans with her expert tongue.

With a loud groan of pleasure, Spike thrust upwards on last time as his orgasm took over making his eyes roll back, flickers of green flame escape through gritted teeth and his hips buck as he shot a thick jet of his cum into the back of Twilight's throat. Several more shots of Spike's molasses-thick, salty cum entered Twilight's mouth as she greedily gulped it down, savoring the delicious and unfamiliar taste of Spike's seed.

When Spike's long and powerful orgasm died down, Twilight pulled her lips off of Spike's thick cock, letting the rest of his cum dribble down his shaft. Spike panted heavily as he watched his sister scoop up some of the cum that had leaked from her lips, putting it in her mouth and hungrily sucked it off before releasing the finger with a wet pop. With the sexiest thing Spike would ever see done right in front of him, his cock was just as painfully erect as before, standing straight up and spewing even more pre.

"Holy crap, Spike! You're hard again?" Twilight asked, standing up and showing off her clean shaven and baby-smooth pussy to her little brother, spreading her legs and letting a drop of nectar drip from her wet folds. "Now, we'll, like, have to do something about that. Won't we?" She giggled, moving over Spike and straddling his lap, rubbing her hot slit up and down Spike's huge shaft.

"Twilight... Please be gentle..." Spike whispered, looking up at Twilight in slight fear.

"Awww... I could never hurt my little brother!" Twilight cooed, pinching Spike's cheek and kissing him on the forehead. Twilight picked one of her breasts up, squeezing it and pinching the nipple. "Open up, Spike." Twilight said, bringing her breast closer to Spike's mouth. Spike instinctively took the nipple in his mouth, sucking and kissing the breast like it was his own mother's teat. Twilight cooed as she looked down at her eager-to-please brother, suckling on her teat like a puppy. Twilight took her one free hand and grabbed Spike's rock hard cock, lining it up with her wet cunt and slowly rubbing the pulsating head against her burning, pink pussy.

Without warning, she planted her body down on Spike's long cock, spearing her pussy as she connected her crotch on Spike's lap. The pair moaned loudly as they got used to the feeling, Twilight trying to adjust to the biggest cocks she had ever taken and Spike trying to deal with the immense amount of pleasure that Twilight's hot, wet insides were giving him. Twilight slowly raised herself off Spike's lap but was stopped when Spike but a hand out in protest, taking her breast out of his mouth as his face contorted in pleasure.

"Wait... I don't want to cum too soon..." Spike groaned as Twilight precariously lowered herself back down.

"Aww, always the gentleman." Twilight cooed, wrapping her arms around his neck and placing her lips on his. Spike was shocked by the sudden kiss but slowly melted into it, wrapping his hands around Twilight's waist as she pushed her tongue into his mouth, quickly exploring the new environment and battling Spike's tongue in an act of dominance. As her and Spike's tongue danced in passion, she pushed herself up Spike's cock, shivering as she did and causing Spike to moan loudly into her mouth. She broke her kiss with Spike as she gasped, feeling Spike hit a certain spot she had only ever reached herself with magical aid.

Twilight gasped and moaned as she rammed Spike's huge cock inside herself, shaking as she planted her hands on Spike's head, gripping his hair as she rode him. Spike did something similar, reaching his arm up to Twilight's horn and tightly wrapping his hand around it and twisting, making Twilight gasp, shudder and ride Spike with even more gusto, slamming her hips down on Spike as if she was trying to break his pelvis. Twilight began to roll her hips on Spike's length as she started to moan his name, and on one smooth roll of her hips she rubbed against a particularly spongy patch of flesh in her vagina and screamed Spike's name, readjusting herself so Spike rammed against her G-spot again.

The combination of the hornjob and Spike beating her G-spot into submission made Twilight scream as heavy waves of pleasure tickled her. Her vaginal walls constricted and pulsed around Spike's thick shaft, making Spike groan loudly as he released his second load of the night into Twilight's cunt, shooting a thick shot of cum which splashed against her cervix. As Spike continued to shoot his seed inside his sisters pussy, Twilight's long and lovely orgasm died down while she continued to grind on Spike, coaxing all the cum out of him.

Spike flopped onto the couch, exhausted by the night of passion as Twilight fell next to him, cum leaking out of her gaping and well-fucked vagina. She pulled her robe over herself and closed her eyes, her exhaustion finally took over. But before she passed out, she turned to her new lover and smiled.

"Thank you, Spike." Twilight whispered as Spike drifted off into sleep.