Spike had to admit, life wasn't too shabby for him right now.

He took a bite from his thick sandwich and chewed, savoring the subtle taste of the various vegetables and meats in his mouth. He only stopped chewing to let a low, strung-out groan leave his food stuffed maw as Twilight reached a particularly sensitive spot on the curve of his penis.

"Ohhh fuck, Twi..." He moaned through the mushed sandwich in his mouth as Twilight bobbed her head up and down his wide shaft, gliding her tongue against the taut skin of his cock. She smiled into Spike's cock and starred up at him with a pair of wide and innocent eyes. She pulled her moist lips up Spike's length, trailing the tip of her tongue up the bottom of his cock until it was all the way off.

"Heheh. Do you like that? Are you close?" She asked, tightening a hand around Spike's dick and beginning to jerk him with a snug grip. She giggled as Spike winced in pleasure at Twilight's hand twisting along his member, her saliva acting as a natural lube to let her elegant hand glide up and down with ease.

"Mmmmmyep." Spike moaned in response. Twilight smiled and began to increase the speed of her tight tugging, making the man wriggle under her grasp until one last quick tug of her hand caused him to cum. He threw his head back and groaned loudly as a hot missile of his seed shot forth from his cock and splattered against Twilight's cheek, staining her face with a searing hot stream of white fluid. Twilight moaned in delight as the volley continued to shoot from Spike's cock and land on her smiling face, straight fringe and bouncing breasts.

After Spike came down from his orgasmic high, he stared down at the happy little bimbo resting on her knees. She was looking up at him, rubbing the ropes of cum in and around her lips with a pair of perfectly manicured fingers, moaning as the taste of his cum stung her tongue with its potent bouquet of salty flavors.

"Mmmmm, thanks, baby. That's a super tasty load!" Twilight giggled, ducking her head and giving the head of Spike's cock a quick kiss.

"Ahhh man, Twi. How do I keep my hands off you?" Spike joked, straightening his back from his relaxed position and admiring his sister's body as she got back on her feet.

"Hehehe. I have noooo idea. But you'll have to for a lil' bit, cus' I'm gonna do some research in the lab~." She explained, turning around and walking away, not even bothering to grab a towel and clean the cum off her face.

As she walked away from her lover she put a prominently wide sway in her hips, dropping them from side to side as she strutted away. Spike would have enjoyed the sight of her lovely, curvy hips and pert ass walking away from him, but as he stared at her assets he could only remember how he still had not taken out his 'royal duties' on the magical princess.

He had successfully cum in all the other girls and was still waiting on to find out whether he was successful or not, but for some reason, he could not bring himself to do the same to Twilight.

He hadn't even thought up with a way to knock Twilight up so she would be none the wiser, but nothing seemed to work in the recesses of his mind. Twilight was strange, big names and dates were lost in her empty mind but little details were always remembered. But not only that but he just couldn't motivate himself to actually do it. Was it because she was Spike's adoptive sister? Spike was fretting about telling his family why their daughter was knocked up with his child but that wasn't the real reason.

Truth was, Spike just felt wrong doing it. He felt wrong about doing it to any of them. What he was doing to them was a violation of their human rights, no matter if it was endorsed by the monarchy or not. Anytime Spike thought about it his own mind shamed him as a disgusting rapist. Sometimes he couldn't even bare to look at Twilight or the other girls, and even if he did he would lose hours of sleep that night as he tormented himself about it.

He didn't feel like doing anything today. Just crawling up in a ball and sleeping.

But then the regal voice of his Princess rung in his mind.

Spike. For the good of Equestria... You have to impregnate your friends.

Spike sighed and raised two middle fingers up in the air, whispering a small: "Fuck you, Celestia." He sighed through his nose and made a promise to himself to impregnate her within a day...

A few days...

A week...

As soon as possible...

He once again sighed and rested his head on the table.

The safety of Equestria is in jeopardy because of my laziness and fucked-up moral compass. Spike thought, closing his eyes

"Fuck." He muttered.

Spike smiled a hollow smile to himself as he read his comic book. It had just arrived today and he was already convinced he was hypnotized by the characters printed on the pages. Even though he read his mind was racked with guilt and depression over his procrastination and breach of trust with his best friends. But he was ignoring that.

Of course, Past-Spike would punch his present self if he ever found out he’d one day consider having hot sex with beautiful women multiple times a day to be “stressful” or "depressing".

However, just as Spike was approaching a juicy section in the comic's story that would distract his mind he heard his name being called from down the crystalline hall. He sighed and rolled his eyes as his concentration was broken and the calling of his name continued. He huffed like a child and jumped up from his bed, walked out the door and traveled down the hallway to see Twilight standing there in her lab coat and nothing else.

Spike wasn't complaining but his brow did furrow in confusion as she saw the busty, nude woman in a starch white lab coat.

"Oh, there you are! Couldn't you have, like, hurried up a little, huh?" Twilight asked, tapping her foot. Spike was about to retort with a snappy comeback but he looked at Twilight and noticed a large amount of agitation apparent in her usually smiling face.

"Sorry, Twi." Spike simply apologized to save himself from a scolding from Twilight.

"Well come on now. I need your help in some super smart studies." Twilight ordered, turning around and walking into the laboratory she set up in her castle.

"So Twi... Why are you naked?" Spike asked, stepping into the lab to the sight of several large, blinking machines and a long set of flasks and beakers laid out on a steel table. After the old library was destroyed by Tirek, Twilight had ordered some new equipment and had re-purposed one of the many rooms in her castle into a lab.

"C'mon Spike. I'm not naked, I'm wearing a lab coat." Twilight said, spinning in place to flaunt the long coat hanging off her naked body.

"Alright," Spike said rolling his eyes at Twilight's difficulty. "What do you need me for?" He asked in a deadpan voice, clearly annoyed he had been taken from his comic books.

"Y'know I've been working on that thing right?" Twilight asked in her usual valley-girl style of speech.

"No." Spike sighed.

"The potion thingy. Y'know the afro-doozy-ack." Twilight mispronounced.

"Do you mean aphrodisiac?" Spike asked.

"Whatever. The problem is that the effects are meant to kick in within a few minutes but I tried it like fifteen minutes ago and nothing's happened yet. So I need you to try one. Just to, like, make sure, y'know." Twilight explained, picking up the clear flask filled with a sparkling deep purple liquid. She thrust it into Spike's hands, smiling at him.

Spike eyed the flask up, inspecting it for any strange little bits and pieces floating around in it. After he saw it was clear of any extra 'ingredients' that might cause suspicion, he brought the vial towards his nose and took in the scent of it, noticing it was basically scentless but for the slightest hint of metal, iron probably.

Spike was still skeptical but knew Twilight wouldn't do anything to hurt him or cause discomfort. He put the vial to his lips and tipped his head back, slowly drinking the liquid back and noticing the slightly sour and metallic taste. Once he finished the drink he put it down on the table and burped lightly, making Twilight cringe.

"Ughhhh. Gross, Spike!" Twilight scolded, slapping Spike on the arm with a mouth open with disgust.

"Hehehehe, sorry." Spike chuckled. He stopped chuckling and waited for any kind of result from the potion, whether it be mental or physical...

But nothing came. No feeling of change in his body or mind came. He just felt... Normal

The teen shrugged and turned back to look at Twilight who had her back turned to him, her starch white lab coat cascading past her thighs and wrapping around her round, pert butt, making a twitch shoot off in Spike's grey sweatpants.

"Anything?" Twilight asked as Spike ducked down and began to tip-toe over to her. Twilight yelped loudly as she was suddenly whisked off her feet and set down on the cold, metal counter she was working on. She looked at Spike, slowly descending to his knees to between her spread thighs.

"I'm feeling more horny. Although that's probably only you." Spike whispered as he leaned into to make contact with Twilight's lips.

"Nuh-uh!" Twilight hummed, shaking her head. She flicked her wrist at Spike, slapping him lightly across his temple. She then pushed him away from her pussy. While she would love a bit of head from Spike, she had very important work to do. She slid herself off the chilly surface and back onto her feet. "I've got stuff to do n' stuff."

Spike sighed as she turned back around to look over her complicated chemistry test, although his sulk was broken by an attention-grabbing cough from behind her. He turned to see Twilight bent over the metallic surface, her lab coat hitched above her ass and her cheeks spread. Spike saw a brief glimpse of her beautiful nethers before she straightened her back and let her singular article of clothing drop to cover her bare bottom.

"I'll be, like, an hour. Choose some lube from my bedroom and I'll let you fuck me up my butt~" Twilight giggled, turning back to her work.

Spike shook his head at his sister's antics and walked off, chuckling to himself. He made his way to Twilight's room to pick some lube from her vast collection while Twilight continued working, both of them paying no mind to the potion secretly working in their bodies.

About forty-five minutes had passed from the 'experiment' and Spike was sitting on the sofa, winding to the end of his comic book. Just as he was about to travel his eyes down to the final panel on the page, he was rudely interrupted by a strange, deep rumbling in his stomach. Huh, that's weird. I just ate. He furrowed his brow as the strange, alien noise continued but quickly shrugged it off when it stopped and flipped the page of his comic.

He became a bit more concerned with the unfamiliar sound coming from his stomach when it returned. However, this time he noticed it to be longer and louder than last time.

He rose from his seat and began to walk towards the bathroom, it didn't feel like the normal kind of stomach upset that a gem binge might bring but it was best to feel sure. But he was stopped in his tracks by a deep pressure forming itself in his core muscles. He keeled over and stumbled to a nearby wall as a hard knot was formed in his abdominal, creating a groan of dull pain from Spike's mouth. After a few more seconds he felt the strange cramp slowly disappear and slowly regained his ability to stand straight.

Just as he arched his back to a straight position another deliberating pain traveled through his body, making him fall to his knees. He released another pained groan as the feeling of tenseness and pressure spread through his body, covering every inch of his muscle. The pain, once again, quickly dispersed and Spike was left with another strange feeling throughout his body.

A foggy haze slowly filled his mind, making it hard to focus on the more physical changes he was going through. His already well-defined muscles began to tense and relax at quick intervals, slowly swelling and churning with each contraction. His legs stretched out behind him, growing fast and long while still keeping the thick muscle that covered him. This went the same for his arms and torso which grew and lengthened with his muscles. As his whole body swelled and grew to a larger size, his genitals followed suit. His already large thirteen incher quickly hardening and growing to an absolutely massive eighteen inches. His balls sank lower, swelling to a larger size than his already impressive nuts.

Spike groaned as his body transformed further, his mind growing more unfocused and clouded as the unnatural changes to his body continued. By the time the peculiar metamorphosis stopped, Spike's muscles looked like that of a professional bodybuilder, he was over seven-and-a-half feet tall, his dick was over twenty inches long and his balls hung down below it at an incomprehensible size that resembled soccer balls.

Along with the physical changes came psychological ones. Spike's mind was now incredibly simple. His head was now fully clouded and unable to figure out what had happened, why his body was like this and even who he was. He lost all recognition of himself and any previous memory he had taken in from his life and could only recall a few key details, like the sky was blue or the sun was hot. The still intelligent enclave within his dumb brain tried to remember a few words to restore his cognitive abilities but all his mouth could do was growl or mumble words like 'pussy', 'cock', 'cum' and 'fuck'. But most of all, a powerful and primal sense of duty came from him. He sought after deep, animalistic itch that had been wired into his mind from birth. A chance to contribute to evolution. A chance to throw his own blood into the gene pool.

A chance to breed.

He let a low, gravelly growl escape his throat as he climbed to his feet, his cock and balls swinging freely under their own truly gargantuan weight. He felt a deep, overpowering need churn in his loins. I need to cum. Preferably in a womb.

His dumb brain managed to remember that he lived in the same building as a person called Twileet or something. Something with a fertile womb he could impregnate. He stumbled down the large halls of the unknown building to find the woman, moaning profanities to himself as his massive, rigid meat pole leaked excessive amounts of pre-cum onto the floor, creating a salty breadcrumb trail to where his transformation began.

Eventually, he rounded a corner with thudding footsteps and saw an equally large figure to himself. From what he could remember from his small mind, the purple hair meant that she was that woman with the fertile fuckhole he so desperately required. Although from his limited recollection, she wasn't as large in certain places as she normally was. She, much like him, had grown to be well over seven feet tall and grown in muscularity to a fine, toned fitness. Her breasts had grown from their already large size to huge, round boulders of flesh and fat with large, strawberry sized nipples attached to their centers. Her thighs, ass, and hips were now unbelievably thick and wide and perfect for industrial style baby making.

Twilight turned her head and locked eyes with the large, bulky man at the other end of the hallway, moaning loudly as she saw him. Both their eyes burned with a mutual passion and understanding. They both hunched their backs and galloped towards each other without haste. Their bodies met in the middle of the hall, a heated embrace of muscular hands and arms joining their bodies as they greedily grabbed at each other's bodies. The man formally known as Spike, desperate for his building orgasm to fall on breedable flesh, began to rub his wildly throbbing cock against the soft skin of Twilight's thigh.

However, it seemed Twilight was also equally desperate to breed as she lifted her leg, revealing her hot, swollen, and gushing cunt to her beast of a lover. Spike felt the heat radiating from Twilight's steaming pussy and positioned his dick in front of her large, dripping nethers. Spike, understanding her need for breeding, grabbed Twilight by the thighs and pulled the tall, busty woman off the floor.

"Cunt." Spike growled simply, lifting Twilight higher into the air and letting his massive, aching cock slide between her thighs, rubbing against her burning, equally needy pussy. Twilight couldn't express it herself, but she wholeheartedly agreed with this decision and began to slowly and sensually moan.

"Cock, cock, cooooooooock." She breathed, her eyes rolling backwards into her skull as the rigid surface of Spike's dick ground itself against her puffy lips. While this teasing was pleasant, she needed more. Much more. All of his cock, preferably. She needed to feel Spike's cock spearing her cunt until his precious load of seed was spilled all over her insides. She needed his thick shaft pumping into her like a meaty fucking machine. She needed his seed filling her womb to bursting point. The potion she created had an unexpected level of potency that the normal Twilight would consider too much, but right now...

Because she needed Spike's babies.

Twilight lifted one, thick leg up and positioned her hips so Spike's massive head was quickly pushed into her accommodating pussy. She growled like an animal as it slowly entered her tight, pulsating vaginal canal but yelped as Spike landed his hand on her ass with a pair of rough spanks and lifted her into the air. Spike himself was in his own agitated state and felt similar feelings as Twilight, specifically making Twilight his breeding tool for life.

He pushed his hips forward in one swift movement and filled the entirety of Twilight's aching pussy, all the way to the tight mass of flesh and muscle that was her twitching cervix. Twilight sunk her teeth into Spike's muscular shoulder as she let loose a primal call of sexual arousal in response to her innards being absolutely filled with Spike's pussy-tearing cock. Spike himself opened his mouth and let a low roar escape his gullet as the incredible mixture of his mates boiling hot juice and her crushing tightness enveloped his cock and welcomed it into her sweet breeding hole.

Spike quickly lifted Twilight up again before basically hurling her back down, replacing the empty space inside her moist cavern with his painfully throbbing cock. Twilight screamed as he repeated the action again, railing her delicate pussy with his almost painfully dominant thrusts. Twilight's body was mostly limp now as she simply let Spike go about impregnating her in whatever way he saw fit. Normally she would let Spike fuck her for an entirely different reason based on her love of being dominated and the taboo rush related with it, but right now, her sexual pleasure was no matter in this affair. Only his pleasure mattered as it would bring her the sweet treat of cum inside her.

Spike picked Twilight's limp body up by her arms and continued his thrusting at a feverish pace, resembling a muscular jackrabbit as he thrust into her squirting pussy. His hips were practically a blur as his massive tool made short, quick thrusts into her constricting cunt, making it twitch and shudder around his powerful meat, pushing in exactly the right places to build his much-needed orgasm.

Normal Spike would take the time of his sex sessions into consideration as to make sure the lady had her needs seen to. But this new Spike was only focused on one thing, achieving orgasm as soon as possible. And judging from his heightening pitch and volume of snarls and roars, jerky movements and strange facial expressions, he was close.

Twilight herself was close to orgasm, but deep down she knew there was only one thing that could truly send her there. Spike himself cumming inside her, staining her pink insides with his cum and basically ensuring that her egg was impregnated.

With a sudden planting of Twilight's hips against his own, Spike released a loud, final roar to the heavens as his thick seed rocketed into the awaiting womb of his mate. Twilight could only throw her head back and scream as she felt her normally small womb being absolutely pumped full of gallon upon gallon of hot, sticky, incredibly potent seed. As Spike's cum was filling her pussy, Spike gently bent his knees and dropped Twilight along with himself on the cold floor.

He, of course, kept his still erect and pumping cock inside her while she was on the floor. Eventually, Spike's large, pendulous balls were free of the heavy fluid that filled them earlier as it had all been transferred to his new broodmare who had developed a delightfully large bulge where her womb was, accentuating just how much Spike came.

Just as they were both about to fall into the familiar realm of sleep, they both opened their mouths and mumbled something the other could not hear.

"Cum..."

Author's Notes:

Sorry for the long break guys. I got Fallout 4 for Christmas and it has been taking up a lot of my time. So good to see you all again, and stay tuned for the next and final chapter to Spike's Bimbo Filled Life.

Also, if anyone had any queries or questions about the story and any of it's details, now would be the time to ask them so I can cover them in the final chapter.