Size Difference

by Birdybirdbird

Rating: mature
Tags: My Little Pony: Friendship is Magic, Alternate Universe, Porn, Fetish, Spike, Sex, Twilight Sparkle, Anthro
Length: 12535

Knock a pegasus off course and a villain wins, kick a rock and suddenly Spike’s a hung fuck-machine while Twilight’s a huge, horny, amazonian goddess.

This story was inspired by the designs of Spike and Twilight by the artist Maarthul, especially from 1507750 on Derpibooru. Genuinely, check it the fuck out before reading this!

The butterfly effect: where the smallest changes, such as the beating of a butterfly’s wings, could go on to create huge changes elsewhere.

Knock a pegasus off course and a villain wins, kick a rock in the past and suddenly all female creatures are horny, voluptuous, amazonian goddesses while all male ones are hung, virile fuck-machines.

(In other words, Spike accidentally alters the anatomy of all creatures forever, and his future is all the kinkier for it).

Art by Maarthul
1660142 on Derpibooru

Published 2024-08-16 18:40:00 UTC
Last updated 2024-08-16 18:40:00 UTC

Amorous Amazon

Life sucked!

At least, life sucked for Spike, or it felt like it did anyway.

You see, recently, Spike had been spending a lot of time rethinking his life, and he felt he had a lot to think about.

It wasn’t easy being an anthropomorphic dragon in a world full of anthropomorphic ponies, but that was the life he’d been thrust into. From an egg, he’d been made an honorary pony, and his entire life had been planned out for him from there.

It wasn’t that he didn’t like living with ponies - they were great - but what was bothering him in particular was his life in general. He’d finished dragon puberty about a few months ago, and only now did he realise how little he had going for him in life:

He had few friends that weren’t just friends of friends, he lived with who was basically his sister, he had no job and was too busy being Twilight’s assistant to get one, and worst of all, he just felt unappreciated overall.

He worked hard for Twilight all day, and what was his reward? He understood she put a roof over his head, but she never even gave him any pocket money, nevermind asked to return the favour. A lot of the time she didn’t even thank him!

Surely he couldn’t be blamed for wanting to be appreciated more…

It’s not like his pursuits of Rarity were going anywhere either, so what did he have?

Those thoughts were what had been occupying his mind ever since puberty ended, though he hadn’t brought them up with Twilight. What would he ask for? A reward for being her dutiful assistant when she already let him live here for free? He’d just sound like a jerk.

Either way, it bothered him. Even if it was being a little greedy, it wasn’t too much to ask, right?

Maybe he’d bring it up with her soon then. Or maybe he’d keep moping.

Yeah, that sounded easier.

Spike woke up in his bed on a morning like any other. Unfortunately, the sleep hadn’t done anything to dispel his glum mood, but he’d expected that.

Yay. Another day of this. Another day of the same monotonous routine that he’d been doing for years now. Lucky me.

Despite wanting to keep laying here and doing nothing while more sarcastic thoughts about his situation plagued his mind, Spike knew that as a princess’s assistant he had things to do, so grumpily, he got up.

Always work, work, work. He couldn’t be blamed for his mood, in a way, but at least he tried to keep this pessimism from his friends. He’d learnt enough about friendship to not make others miserable just ‘cause he was. But does Twi’ ever give me a pat on the back and a ‘well done’? No!

Tossing the sheets off himself, Spike stood up, having slept in the nude. First he needed to get dressed, so after his bare body was displayed to the room, he shuffled over to the drawers his clothes were kept in.

He liked his body, or at least, he couldn’t complain. His form was quite lean and muscular, he wasn’t a bad looking dragon, and most importantly, he even had a purple cock and balls which he thought weren’t a bad size. Overall, he liked it.

Pulling out some underwear, he put them on along with some of his casual, unimpressive clothes. It wasn’t the most visually appealing outfit, but it did the job just fine.

Now, it was time to check the schedule. Spike practically knew it off by heart by now, but still liked to double-check; a byproduct of living with Twilight he imagined. Okay, it’s… this day, so today I’m supposed to…

First, he got up, got dressed and made Twilight breakfast, and then-

Oh, it’s experiment day. His face dropped even further. Experiment day was the one of the couple days a week where - you guessed it - Twilight did her experiments, the same ones that she always used Spike as her little lab rat for.

After that he was to clean up the crystal castle a little, and then he had the rest of the day to himself, though it wasn’t like he had much to do in his free time.

Oh well, I might as well get to it then. Double-checking he wasn’t forgetting anything important, Spike put on the most neutral face he could and headed to the kitchen. He had work to do.

This morning, it was pancakes. Not the most original option, but one of the easiest ones that he could be bothered to do. So here at the counter he stood, frying pan in hand, working away to make Twilight her meal before he made his own.

It was fine.

Before he’d finished making a full stack of them, in Twilight walked, sniffing the air. “Hey, Spike. Pancakes today?”

“Yep.” Keeping the answer short, he turned to look at her heading to sit down. Twilight looked the same as she always did on these days. With a lab-coat on over her casual clothes, she was floating some scrolls beside her and didn’t even notice his eyes on her.

Under the lab-coat, she wasn’t anything impressive. With a body a darker purple than his, Princess Twilight wasn’t exactly known for her body like Celestia or Cadence, instead, she was quite a more modest mare, with a moderately bouncy ass and an average chest. She’d done some growing since becoming an alicorn, but not much. That being said, he only came up to her shoulder, so she definitely had grown because of it.

When she sat down, Spike’s eyes returned to the pancakes.

They both did their respective tasks in silence, the only noises being of paper rustling and pancakes sizzling. Eventually however, the food was done, and Spike presented a large stack of pancakes to the princess alongside any toppings she could possibly want.

Looking up from one of her smiles, the mare spared him a quick smile. “Thanks, Spike!” Her head moved back down immediately though, and she went back to whatever it was she was doing with that scroll.

Holding in a sigh, Spike moved back to the counter. She could easily magically make herself the pancakes with no effort and in a fraction of the time, but still he was doing it. She didn’t even need him as her assistant anymore.

Maybe he could bring up the idea of stopping being her assistant soon. Or better yet, he could keep avoiding the subject with her.

Spike picked up the rest of the pancake batter. There was barely enough for him to get a couple pancakes. Oh well.

“Alright! I think it’s time we get to experimenting!” Standing up enthusiastically, Twilight clapped her hands together as her horn lit up, and the scrolls floated up again as she strolled over to the door. “C’mon, Spike. I’m feeling good about this time!”

The alicorn always got excited about new experiments, which led to her barely even looking back at him as she eagerly marched out the kitchen door.

Resigning himself to his fate, the dragon finished his cleaning up and followed after her, purposefully keeping his eyes off of the barely-touched pancakes left on the table.

Soon, after a short stroll filled with an egghead’s rambling, the two arrived at the library, their designated experimentation room. With magic, Twilight thoughtlessly opened the doors and went in first, and Spike was right behind her, ready as always.

Determinedly, she went to the middle of the room, and holding up a scroll spoke to him. “So, do you remember how Starlight made that scroll that went back in time? That one that showed us all the alternate universes of what could have happened if Rainbow Dash didn’t do her rainboom?”

Spike stopped behind her. “How could I forget? That was one of the weirdest adventures we’ve been on.”

“Well, after some working together with her…” She dramatically turned to him, gesturing to the scroll. “I remade it.”

There were many ways Spike could have responded: he could have been shocked that they’d been able to considering it was destroyed, he could have been cautious at how this would involve him, and he could have even been outraged at the fact that she’d brought back such a dangerous thing.

But he didn’t feel any of that. In all honesty, Spike wasn’t in the mood to care, so as casually as he could, he feigned interest and went “Really?”

Twilight didn’t notice. “Yeah! And best of all, I even improved it!” Holding it aloft, the mare began her rambling. “Now, instead of the spell taking us a set amount of time into the past and back, we can visit any point in previous history! Any! The spell just drops you off at the start of the day and then you can visit the past!” As she rambled, the mare began pacing back and forth. “Of course, we’d have to be careful not to make any changes to history, and not to go to a time we already exist in because this spell overwrites the mind of our already existing self, but as long as we avoid those two things, we could watch historic events take place, see historical objects in more than picture books! The applications are near-limitless!”

When the nerdy mare stopped, she turned to Spike, a bright smile on her face. “So you want me to…?”

“Go back in time so the spell can bring you back. Then tell me everything you saw.”

Another day, another experiment. He’d gone through a lot over his lifetime of being Twilight’s test subject, so he was entirely used to this by now. Hopefully this’d be over pretty soon so he could get a headstart on the cleaning. “Okay then, when do we start?”

The princess showed a little shock at his enthusiasm, but her eyes moved back down to the scroll to answer him instead of questioning him. “Well, whenever you’re ready, I guess.”

He nodded, and Twilight got the message.

I… guess we’re starting now then. She expected him to want some debriefing or something along those lines, but if he wanted to get right into it, she wouldn’t complain.

Looking down at the main scroll of her collection, the others now tossed to the side, Twilight read through it one last time. She’d done it plenty already this morning, but after quickly checking over it for the twelfth time, she felt she was ready, and her horn lit up with the immense power of an alicorn.

“Okay, so I don’t want you accidentally being teleported on top of a group of random ponies and changing history irreversibly, so what I’m gonna do is teleport you back to before any creatures evolved altogether. That way we can’t accidentally alter history.”

“Uh-huh.” He was listening, just probably not enough.

As her horn grew brighter, a strain was put on Twilight, and she grit her teeth as the spell neared completion, the light almost blinding. “Good. And remember the butterfly effect, s-so make sure not to-“

Before she could finish, the spell was conjured and climactically cast on Spike, a big blast hitting him in the chest but him feeling no impact. “Huh? What-“

But then, a colossal cauldron filled with purple magic appeared out of nowhere, and sat directly above him. At first, Spike was caught off guard, but he did nothing to stop when the spell ignored gravity and pulled him upwards into it. He remembered how this went last time.

Twilight didn’t seem to be affected by its pull, and when he was sent flying up into it, she stood where she’d been and just watched as he disappeared from view.

“Aaaaaagghh! Woah!” Spike flailed his limbs around as he was pulled through… this. It was a purple gateway to the past he assumed, and just like when Starlight had done it, a rotating hourglass appeared and spun around before disappearing from view.

The dragon couldn’t keep himself straight, and kept spinning wildly in here for Celestia knows how long, but after waiting way more than he had to last time, the end presented itself and threw himself out carelessly into the past.

“AAAAAHHHHH” Thud! After falling from however high up the Crystal Castle’s library had been and hitting the ground roughly, the dragon was just appreciative that he had no broken bones, though he still had to rub the sore parts of him that’d taken the hit. Ugh. Those are gonna bruise.

Picking himself up and dusting himself off, Spike took a look at his surroundings and was thoroughly underwhelmed. He’d been expecting something exotic and exciting, and instead all he got was a pond.

“I should have seen this coming. Why would any of Twi’’s experiments lead to anything interesting?” Grumbling moodily, the dragon paced. Apparently, being sent back an insanely long amount of time ago wasn’t enough to end his bad mood. “Like, why couldn’t Twi’ just use a random item or something? Why’d I have to go? So I could tell her about some dumb pond?”

Glaring at it, a rock on the small shore before him caught his attention, and then caught his ire.

He had to blow off some steam, so why not?

Bringing his foot back, Spike took a swing at it with his bare foot, and watched as it made a tiny splash and a ripple before sinking down into the depths of the pond.

He didn’t really feel better, but it did help, at least a little.

Turning away from the water, the lizard went to pace and fume a little under the rising sun while he waited for anything to happen, but before he could take another step, the cauldron reappeared.

He didn’t question it, at least he could be taken back to the present so this could be over.

Wordlessly, the dragon let his body get pulled up into the portal again, and Spike got ready to see Twilight and tell her about the pond. On the bright side, at least there was nothing here I could have used to change the future with.

How wrong he was…

As he would soon learn, his actions had led to a change in history.

Knock a pegasus off course, and suddenly the villains have won in that world. Kick a rock at the beginning of the evolution of all creatures…

It was fine, it wasn’t like he kicked the rock into the pool that everything to have ever existed originated from, altering the DNA and future evolution of all male and female creatures to come after.

Oh wait, that is what he did. Oops.

Ugh. Hm? What the heck? Spike woke up in his bed on a morning like any other. However, having returned from the past, he bolted up in bed. What the-? Why am I-?

He was nude again when he’d just been wearing clothes, and he was in his bed again. Why?

Think, Spike, think. You’re a smart dragon. Still sat up in his bed, the dragon tried recollecting what Twilight had said, though he hadn’t been listening too well. From what he could recall though, he did remember her saying something about the spell sending you to the start of the day, and something else about you overwriting the mind of the you already existing then. I guess that just means I’ve gotta do today’s morning all over again.

He wasn’t exactly thrilled to do it, but it wasn’t like he had much of a choice.

Fine then. The dragon went to swing his legs off of the bed like he usually did, but something stopped him that made him freeze. Particularly, something felt… different between his legs, and he was almost scared to know what.

After hesitating a ton, mostly from wanting to know why something had changed from the other this morning, and wanting to avoid knowing why his junk suddenly felt weird, Spike still didn’t do anything. But he had to move eventually, he couldn’t just wait here nervously forever, so after a minute of failing to figure out what was happening, he just decided to get it over with all at once.

O-Okay… Three… Two… One… Hurriedly, Spike got himself up out of bed and stood beside it, but right when he got onto his legs, an unfamiliar weight pulled him down, and he could feel exactly where it was coming from.

To put it bluntly, his cock and balls felt heavier, much heavier, and unable to resist knowing what the fuck was going on, Spike finally look down.

What he saw baffled him.

His entire body was the exact same as before, as muscular and lean as it had been, but between his legs now, where his ordinary junk had been, there was a pair of ridiculously huge testicles weighing him down that put together were the size of his head, each filled with an abundance of his fertile dragon seed, along with a gigantic beast of a cock that dangled down past them, reached his knees, and put the most gifted of members he’d seen all to shame with its terrifyingly impressive length and insane girth. Even its veins screamed virility, and Spike’s jaw dropped.

For some reason, the new him was fucking hung, but Spike wasn’t complaining. He’d been happy with his bits before, but to have the genitalia of a god just dangling down there... Well, it was one step closer to clearing up his bad mood.

Though he didn’t know where this change had come from, the hyper-sized parts between his legs let him know that something had to have happened in the past, something had to have changed that led to him gaining this, but wha- The rock!

Though the absurdity of it all was not lost on him, that was the only explanation. He’d done this, and he’d caused the future (or rather, the present) to give him this.

Nice job, me.

He could get used to living in this new world.

When he eventually came down from the sudden sense of pride that his new ‘improvements’ gave him, Spike was tempted to get back into his bed and take the thing for a spin with both hands, but then, his mind returned to the present.

Yes, he had a new body he could be doing some of his own ‘experimenting’ on, but he still had things to do. Monster cock or no, he was still Twilight’s assistant, and as of now he had a day to prepare for.

With his mood significantly improved, Spike tried strolling over to his drawers, only to discover these new testes were both a blessing and a curse. He figured it out eventually, but with his legs not able to close fully, he had to walk with them quite spread.

He got there in the end, and on reaching his drawers, could finally get dressed. “Okay, let’s see what we’ve got.” Something that could at least try to hide these things would help. Considering his member when flaccid was still longer and thicker than his forearm, he didn’t have much hope.

Opening the drawers, Spike expected to see all his usual clothes, all of them arranged exactly how he’d put them. That wasn’t what he found.

Instead of his normal clothes, there were multiple pairs of the same items of clothing, and that was it. There wasn’t the multiple outfits he’d bought over the years, just multiple greenish-white tank tops and a few pairs of small green and purple shorts.

Looking around, he couldn’t find any underwear, either…

Spike’s mind raced, but he didn’t have the time to be panicking, he had a breakfast to make soon, and if this was what the Spike that he’d replaced wore, then this was what he’d have to wear.

He threw on the clothes and tried getting used to them, but struggled. The tank top wasn’t too bad. It showed a bit too much skin for his tastes, but he’d settle for it. What was the real problem were the shorts.

If they’d looked small before, they looked even smaller on him now, and worse than that, they hid nothing. Not only were his balls practically visible under the fabric, leaving next to nothing to the imagination with the huge bulge in the front, but his cock literally left an outline on one of the shorts’ sides, and he could even feel a slight breeze on its bare skin.

The outfit altogether was skimpy, and was showing off his muscles as well as everything downstairs.

But he had to suck it up. Why?

He. Had. Breakfast. To. Make.

As much as he was willing to quit his job as her assistant, his loyalty was unwavering, and as long as he still worked for her, he was still going to do his jobs. Plus, there was quite literally no other choice of clothing, and this must be what he always wore in this time, so Spike decided he’d get used to it, and moved on.

Next up was the schedule. It’s experiment day again then, isn’t it?

Wrong again.

For some reason, rather than saying what it should’ve, today was labelled ’Gym’ on the schedule, and Spike hoped that he didn’t need to already know what that was to do the chores needed for it.

Why did the schedule say ‘Gym’ anyway? It wasn’t like he ever went there, his muscles were built from being an excellent assistant, and he knew Twilight wouldn’t be in one of them in a million years, so why? Did Ponyville even have a gym?

He’d have to figure it out as he went, he was behind schedule enough as it was.

Okay. Breakfast time. Maybe I can figure out what happens on gym day there. The thought of trying to change time back to how it’d been hadn’t even crossed his mind yet, but if this new timeline’s only changes were he was absurdly hung and wore oddly revealing clothes, then maybe he was fine staying here.

Still getting used to walking with two incredible cum-tanks hanging off of him, Spike made his way to the kitchen, and along the way thought of how best he could hide these things from Twilight. If anything, it was like his clothes were trying to show them off, so he was out of ideas.

Like everything else, he supposed he would just have to go with it and see what happens.

Soon, he reached the kitchen’s gigantic doors. Along with his own bedroom’s doors, and a bunch of other things around the castle he’d seen on the way here, they seemed much bigger than usual, but he ignored it and went to head inside.

Grabbing a conveniently sized handle perfect for him and not noticing the other, larger one far above it, Spike heaved open one of the doors, where he was met with an imposing figure looking down on him from the other side.

They were gigantic, and were even blocking out some of the light behind them, making them look even more intimidating, but after craning his neck to see their face, Spike saw who it was.

It was… Twilight.

He took the moment to look at her new body, and then kept doing it.

She was so different, in so many ways, and he noticed every single thing there was to notice about her. Firstly, whereas he used to be up to her shoulders, now he was barely above her hip, and she was twice his height. Speaking of her hips though, that was where he noticed some of the more… ‘noticeable’ changes.

She used to be thin, a little curvy in some areas but overall as attractive as you’d expect from an egghead.

This was not that Twilight.

Now, her hips were wide, bountiful, and the hottest he’d ever had the honour of seeing on a mare, and that was only accentuated by her gigantic thighs that he could stuff his entire face into.

Meanwhile, further up, it only got better.

Twilight used to barely have tits, she had some, but they were smaller and perky, not to Spike’s tastes. These however…

They were like two ridiculously massive balloons sticking out of her chest. They looked bouncy, they looked squishy, they both individually looked bigger than his entire head, and they looked like they’d be perfect to stick his new and improved cock between. Spike wanted nothing more than to have them in his claws.

Her face looked the same, but that wasn’t a bad thing; the mare had always had a cute face.

And all over the rest of her, on her arms and her legs and her belly and every inch of her powerful, perfect body, Twilight was rocking a muscular physique, and looked like she could break him like a twig.

His Twilight from before didn’t go to the gym. This one did.

If the raging muscles weren’t enough of a clue, then her outfit was. The alicorn looked ready for a thorough workout, and so was dressed fully in clothes that fit the occasion. In a purple darker than her own body, she wore leggings, ones riding halfway down her hip and giving him a full view of the camel-toe she had showing through them, and along with that, she wore a sports bra, one seeming like it barely fit her with how far her tits were stretching it, and that would generously release them into the world at any moment.

The mare didn’t look like she had a trace of fat anywhere on her, except in the pudginess of her thick thighs and her monumental mammaries.

She wasn’t the nerdy, reclusive Twilight Sparkle anymore, this… this was an amazonian goddess of sexuality.

And Spike wasn’t complaining, nor was his excitable body.

But after so long spent ogling her, lost in her unending curves and letting arousal overcome him, Spike almost didn’t hear what she said, fortunately though, she was shouting, and when his head snapped up to hers, he noticed she was glaring too. “Spike! Don’t ignore me! Where have you been?!”

She looked pissed, but he was too affected by her body to answer her. It was partly because he was enamoured by it, and though he couldn’t take his eyes from hers, his eyes demanded that he looked down. Mostly though, he was stunned into silence by something else, by ‘Little Spike’ downstairs waking up and wanting to make his appreciation of her new body well-known.

He knew that these pathetic shorts would do nothing to hide an erection from who was basically his sister, especially not an erection of this size.

So terribly, Spike tried slipping his hands down to grab at it and keep it from springing up, and only then did he try to answer Twilight. “I- Uh… I… overslept?”

She didn’t seem impressed, but at least she didn’t bring attention to his colossal cock straining against the fabric of one of his shorts’ legs. The massive mare crossed her arms against her chest in an attempt to appear more intimidating, but all it did was arouse him more as she pushed the plump things up. “Just try to be a little more punctual, Spike, especially on a gym day.”

On the bright side, at least this Twi’ lectured him like the old one did. “O-Of course. Sorry.” His meat throbbed in his hands as it somehow grew even larger. It got thicker, longer, and under the fabric, he could feel its veins pulsing with a virile need. Ngh! Why is it doing this?! It’s never usually so… excitable!

This new dick had to be more eager than his last. That made sense, he guessed, it did have more to give, after all.

But miraculously, Twilight ignored his awkwardness, that or she was too bothered by his tardiness to care. Either way though, it blessed him with the opportunity for his massive member to go unnoticed as Twilight turned and walked to the table, her tone brightening considerably. “So, what’re you thinking for breakfast?”

For a moment, Spike didn’t hear her. Every single shred of his attention had been stolen, and as she walked away, it was all centred on the captivating masterpiece that was Twilight’s massive ass. Bounding away and rippling with each step she took, the two ridiculous cheeks looked like they were barely being contained by the tight leggings, and he couldn’t tear his eyes from them. The rest of her was colossal too, but this cake took the cake.

It looked like his hands would sink into them if he went to grope them, and he knew that those plump pillows could give him the assjob of assjobs.

She was the same mare he’d grown up with, the mare who was basically a sister to him, and still he wanted to see her bare-assed and twerking that hyper-sized flank of hers for him, or better yet spreading those hefty things for him so he could shove his face directly between them.

His reverie ended when Twilight sat down. Her massive rear squished down on her seat, and with her pulling a book from somewhere, Spike’s mind got out of the gutter.

W-Wait, didn’t she ask me something? She did, didn’t she? Why hadn’t he answered her then?! He needed to answer her, he needed to answer her now otherwise she might turn around and see him bent over and still trying to hide his ungodly dragonhood. O-Okay, sh-sh-she asked what was for breakfast, right?

Hoping to Celestia she did, Spike fumbled his way over to the counter as casually as he could, keeping his back to Twilight as unsuspiciously as he could.

Unfortunately though, the throbbing down there and the way it strained his shorts didn’t help Spike sound casual.“F-For breakfast it’s, um, p-pancakes.”

Twilight looked up from her book, confused. “Pancakes? I can’t remember the last time you made pancakes.”

Spike prayed to whoever he could that she dropped the issue, and didn’t investigate if anything was wrong with him.

And fortunately, his prayers were answered. “Huh. I guess can be a cheat day then. I’ll just have to work extra hard to burn it off later.” She went back to reading her book, and Spike released the breath he’d been holding.

Okay… Pancakes. He let go of his hung, half-erect cock. Unashamed, it pushed up against the leg it was in, and was immediately obvious to anyone who saw him from any angles but behind, so that’s where he made sure to keep Twilight.

Soon, with mercifully few complications, Spike was hard at work making the pancakes like usual, trying his best constantly to not think about everything he wanted to do to his technically-sister.

And eventually, a stack of pancakes were ready and delivered to Twilight. They were pretty small compared to her now that he thought about it, but as she happily indulged on them, he didn’t think it mattered all that much. At least he’d been able to hide his dick from her this entire time.

Too stressed to even think about making himself any, Spike let the giant alicorn mare finish off her breakfast, and when the last morsel was fed into her mouth- “Mm! Spike! These are really good! If you make these too often I’m not gonna be able to work all this off!”

“Th-Thanks.” When he looked behind him, she was too caught up in her praising to notice him lustily ogling her chest. He looked away though before she could notice him doing it, biting on his lip as his cock pulsed demandingly some more.

By now, Twilight had noticed his odd behaviour, but she wouldn’t bring it up. If he wanted to talk to her about whatever it was, he could. Standing up, she snapped her book shut and teleported it away before looking back down at her number one assistant. “So, Spike, have you got all the water ready for today’s gym day? I feel like working up a sweat today! Plus I’ve gotta burn off them pancakes.”

“Y-Yeah!” He had no clue what he usually did, but at least now he knew he needed water.

“Then let’s get going! Some of the girls might be there already.” In a chipper mood, Twilight went to wait by the door as Spike shuffled over to the fridge for this water, and sure enough, he found it, a small wooden tray with a couple dozen water bottles on it. As he grabbed it though, the mare watching his every move from behind started noticing things, such as how every move he made purposefully worked to hide his front from her. Why is he…?

As her mind worked, fortunately for Spike, the small water bottle tray could be held low down enough to obscure her top-down view of his meat, so with it held at belly-height, he was able to stroll up to her without her even noticing the aroused dragoncock sticking out. “A-Are we ready to go?”

“Huh? Oh, yeah.” Twilight led the way down the halls, with him trailing behind her, but now that she noticed he’d been acting weird, she looked back on breakfast. He had been keeping his back to her the entire time…

As she put pieces together, Spike was lost in something else, specifically, lost in the big, bubbly, bouncing, beautiful buttcheeks right in front of him, the ones that were perfectly positioned for him to stare at them the entire time they walked.

But now Twilight was coming to conclusions, and slowly but surely, she was figuring things out. But why would he have his back to me? It could be to hide something, but what would he be hiding that-

She stopped in place. She’d figured it out! Or at least, she thought she did. She’d need conclusive evidence to-

“Oof!” While the conclusion may have stopped her, it didn’t seem to have stopped the enamoured dragon behind her, so, too busy staring at her rear to notice she’d stopped, Spike had walked right into it. For a few blissful moments, his face had come into contact with her bulky behind, but then afterwards, he was send tumbling backwards onto the ground, with the water bottles being sent all over the place as he dropped the tray.

“Woah, Spike, are you okay?” She turned to face him, but before she could notice anything else, the proof to her theory was practically presented to her as she looked down at him.

“Y-Yeah! I’m fine! D-Don’t worry about-“ It was too late, and no matter how much he tried to hide it, Twilight had already seen it, and she was staring at the gigantic pulsating rod in his shorts. “I-I-I’m sorry, Twilight, I just saw you and I-“ Spike wanted more than anything to explain himself, to have his ‘sister’ think he wasn’t some pervert lusting after her (which he was), but before the dragon got a chance to say much, she reached down, and scooped him up off of the floor. Wh-What’s happening?

Before he knew it, Twilight was holding him in a princess carry with one arm. With one hand planted on his rear, the other was dangerously close to the humongous problem at his groin, the one that had grown to be as long and thick as Twilight’s own huge forearm. Meanwhile, Spike was getting a face full of alicorn tit, not that he was complaining.

Staring at his colossal junk, both the throbbing rod escaping the bottom of the shorts and the humongous testicles hidden from view, eventually, the mare spoke up, speaking in a voice that was stuck between aroused and overjoyed. “You’re saying… I did this to you?”

Ashamed, Spike nodded into her breast, trying his best not to grope or huff it.

But Twilight wasn’t shaming him. “Y’know…” Slowly, enticingly, her large hand slid up the thigh his monster-cock wasn’t on. “If you wanted…” Her fingers gingerly made their way up onto the fabric covering his needy, throbbing length, and Spike sucked in a sharp breath from the contact. “I could give you a little relief, if you wanted.”

On that tantalising word, her hand grasped around as much of the meat as it could, and softly, she clenched down on it, making Spike’s back arch as new incredible feelings shot through him. “Angh!”

“You certainly look like you need it.” In a seductive, almost motherly voice, she kept speaking to him softly, and the dragon was putty in her hand as she slowly stroked him through the material. “It is a little surprising though, I’ve not seen you like this in months. Usually you try to avoid this kind of thing, but if you’d like, I’d be happy to ‘help out’.”

By ‘him’, he assumed she meant the previous Spike in this body who he’d replaced, but why in Equestria would the other him avoid being treated like this?!

As he kept moaning for her, Twilight had an idea, the best one she’d had in a long time. “Hmm. With the water bottles everywhere, I don’t know if we can go to the gym anymore. Maybe we should stay home instead. I’m sure I could find some special ‘exercises’ we could do together in my bedroom if you’re up for it, Spike.”

She was inviting him to… She was offering to…

The dragon had worried his sibling would think of him as a freak for lusting over her and her unendingly erotic body, but instead she was gently stroking him as she offered to ‘exercise’ with him in her bedroom.

He’d never been so happy he’d kicked a rock before.

In her clutches, Spike allowed pleasure to be heaped onto him as one eager hand couldn’t resist grabbing onto the squishy mass that was her humongous breast. “Ngh! S-Sure! What kinds of exercises?”

With a spring in her step, Twilight went the opposite direction they’d been going and took them both to her room. “Oh, you know- Mph! The fun kind!”

And so, as she whisked them away to hers, Spike kept subtly feeling up the fabric over her huge chest. It was just like he’d imagined, as pillowy and dreamy and hot and squeezable as a dragon could ever want. From being held against her chest, he already knew that this Twilight’s musk smelled incredible too.

There was a slight thought in the back of his brain that this was his sister he’d grown up with, practically the same nerdy one in a lab coat that he’d been with earlier, but honestly, he didn’t give a shit. Even if he wasn’t thinking with his dick, this Twilight had a body that was the peak of sexuality, and she was lusting over him too, so if the opportunity to have his way with her came up, he’d take it with no regrets.

His bad mood from before had been entirely forgotten about at this point.

It wasn’t long before the two reached Twilight’s bedroom, and rushing them in, the mare seemed just as excited as Spike did as she slammed the door behind them and threw him onto the bed that was far too big for him. As the comparatively tiny dragon watched, she crawled onto the bed and over to him, a hungry look in her eyes like a predator and her prey. “It’s been far too long since we’ve done anything like this, Spike!”

This was a dream come true for him, and he could hardly believe it. His cock could though, and it was making that painfully clear.

Ignoring his unattended schmest though, Spike felt Twilight’s hand place itself on his chest, and it slowly pushed him further and further back on the bed. “When you first finished puberty, you couldn’t get enough of me and the girls. I don’t know what changed, but I for one am glad you’re back to your old ways!”

His back hit her huge pillows (not the ones on her chest) and sexily, her hand trailed down, and down, and down, until one finger was daintily placed on the hem of his shorts.

He imagined she’d pull them down tauntingly slow.

Nope.

Instead, with a poof, they disappeared from his body completely, and everything contained within came rushing out. His melon-sized testes spilled out onto the bed, and he could feel the shit-ton of spunk stored up sloshing around inside of them. More importantly though, with the confines of his shorts gone, Spike’s gargantuan dong was freed, and with it now able to get fully erect, it stood stiff for Twilight’s convenience, the monstrous fuck-stick and its thick veins throbbing passionately.

The alicorn stared at it, awestruck, and she only broke out of her delirium when some of the cock’s deep, thick, intoxicating musk made its way into her body.

Hotly, Twilight’s hand reached out and grabbed it tight, forcing a moan from her assistant, but rather than jerking it off, she pulled it back a little, and bending down, the mare gave in to the urge to shove her face right into her dragon’s fat nutsack and breathe in.

Snifffffffff!

Huffing the filthy, mind-numbing scent of Spike’s junk that she’d been missing dearly, Twilight kept taking it in like she’d die without it, and all the while, her pussy’s heated juices seeped into the fabric of her leggings. Yeeeeeeessssss!

And above, Spike still had a hard time believing that his sister, who’d suddenly become the most fuckable mare he’d ever seen, was drowning on the musk of his giant balls. But lying back, he didn’t look a gift horse in the mouth, and let himself enjoy the feeling of hot, desperate breaths on his sack.

Twilight spent minutes down there, even touching herself occasionally, but it wasn’t long before she wanted to move on to something more… fun.

Panting, the mare got back up. With half-lidded eyes and a sultry look on her face that Spike never thought he’d see on Twilight, she smiled at him, and her eyes drifted down as she bit her lip. “Sweet Celestia, I forgot how fucking HUNG you are!”

Even though most stallions’ cocks were huge and disproportionate-looking on their bodies, Twilight knew Spike’s was a cut above the rest. Though she hadn’t seen too many in her life, none of them were as ridiculously long, ridiculously thick, and ridiculously perfect as her favourite dragon’s. Plus, that wasn’t even including the ridiculously powerful, productive and pungent cum-factory’s he had weighing him down all day.

She grasped hot, purple skin of his meat again, and loved how even her big amazonian hands couldn’t nearly wrap around the shaft, but better yet, now it was hers to have fun with, and she couldn’t wait!

Seeing him awed by her every move, and seeing his eyes abrasively glued to her tits, Twilight brought a hand under one, and she kneaded its supple flesh as she looked him in the eyes. “So, now me and ‘Not-So-Little Spikey’ down here are finished getting reacquainted, how would my number one assistant like me to give his big fat cock a titjob?”

He wanted nothing more.

Spike didn’t know if it was the dirty talk, that irresistible look on the sexy mare’s face, this entire morning spent lusting over her bountiful body, or the offer of getting to have his cock wrapped in them, but either way his cock was painfully desperate for the mare, so he nodded so needily it was almost pathetic. “NGH! Please!”

With a satisfied smirk, Twilight got onto her knees. Towering over him, she gave Spike a glimpse of the wet patch of her leggings, but he wasn’t looking down there. His eyes were on her chest as she started sliding her sports bra off of her, and he watched as, gloriously, the clothing was pulled over her head, and the two plump yet unfertilised milk-sacs spilled out into the world, dropping down heavily before bouncing and jiggling away in front of him.

The dragon loved them. Before, he’d only seen them contained by her gym top, but with them now fully exposed, he could appreciate them fully.

They did look bigger now they’d escaped their confines, but he’d already marvelled over their titanic size, along with how they felt in his hands. A new thing to see however were the two big purple nipples attached to each udder. Each of them looked just as inviting as the other, and he couldn’t tell which one he wanted to latch his mouth onto first.

Above, letting Spike take in the sights, Twilight chuckled at the lustful look on his face. “You know, you look just as enamoured as when we spent our first night together and I first got to show you these things.” Proudly, she shook her chest a little, and the two melons bounced wildly for Spike’s enjoyment, his eyes following the nipples. “Hehe! Wow! You must be really pent-up if you’re THAT happy to see them!”

It was tempting to tell him to ‘take a closer look’ and let him grope and suckle on her teats like he was trying to get milk out of them, but she wanted to give him a titjob far more. Besides, if his reawakened libido was here to stay, then maybe she’d have ample time to let him do whatever he wanted with her body.

“Now, I believe I said something about a titjob!” Yearning to give him one, Twilight didn’t delay it any longer, for both of their sakes.

And Spike didn’t stop her. With his massive meat throbbing desperately for her and her body, the dragon watched in awe as she lowered her bosoms down and placed them behind his cock. Her eyes looked up and met his, giving him a lustful, sultry gaze, and then, whilst holding eye-contact, she pushed her chest forward, and slowly she let her pillowy teats envelop him, embrace him, and ease his hot, hung girth into the snug gap between her breasts. His tip was still sticking out the top a good bit, right before Twilight’s lips, but that was what happened when a colossal chest met a colossal cock.

“Ngh! O-Oh my gosh!”

“Nice, isn’t it?”

“Y-Yeah.” On one hand, he agreed, though on the other, he thought ’nice’ was the understatement of the millennia. In fact, the heftiness of the giant globes weighing down on his belly and chest was a feeling like no other, and Spike didn’t think that he’d ever felt anything as incredible as having his new cock wrapped in the cosy warmth of Twilight’s tits, and she hadn’t even started yet!

Meanwhile, Twilight was loving how it felt too as its girth was wedged in between her bosoms. She truly had missed her favourite dragon’s cock, and now, getting to have fun with it yet again as it pulsed between her boobs, it was a dream come true.

Looking down at his purple tip hotly, admiring how it looked and smelled and how she remembered it tasted, her hands came to push her breasts together, and with him now being sandwiched between them thoroughly, she began moving them.

Spike wondered if she’d be able to pick them up at all, but to his surprise, she managed. With the muscles in her arms bulging, Twilight impressively heaved her cumbersome chest off of him, and though her hands were sinking into the squishy masses, they were still solid enough for her to pick up with relative ease.

Lost in the act, the mare slowly slid her breasts up his pole, all the way until his tip disappeared into her bosoms. She could feel it pulsating between them, and the nice feeling sent waves down her.

Someone else was feeling nicer though. “Nngh! Oh my gosh! Ah!” It was official, this was the best thing ever. Back in his old timeline, Spike had been the biggest virgin in Ponyville, even behind other virgins like Fluttershy and his sister, and the sensations this new and improved Twilight was sending through him were blowing his mind. Waves of potent pleasure were being blasted through him, and as the happy mare worked down between his little legs, he turned to putty underneath her. “Ahn! H-Holy shit! You’re really good at this, Twi’!”

She smiled, both proud and amused, right before she slammed her tits down. WHAP! They powerfully walloped Spike’s body and nearly knocked the air out of him, but he didn’t complain, even if a grunt escaped him.

“Oof!” The consequences of the impact struck his entire body, and Twilight sent him another amused look, but that was all she did before heaving her funbags back up again, and when they reached high enough-

WHAP!

From the pleasure, Spike’s restless hands longed to dive forward and clutch at her big, grabbable nipples, but they wanted her to continue more, so his hands clutched onto the bedsheets beside him like his life depended on it. “Ahhn! Don’t stop! Keep going! Please!”

She obliged, happy to keep servicing his powerful, perfect, unparalleled dong. Sliding her teats up it once more, when they reached the peak again, she bashed them back down onto him with a loud WHAP! and then didn’t even wait to do it again. Using the momentum of them crashing down on him, she immediately picked them back up, and let them drop down again to send even more ecstasy through his body. And then, she bounced them back up again, and then back down again, and then, Twilight started bouncing her boobs up and down on his cock over and over and giving Spike the titjob of legends.

Each time the ridiculously heavy udders were lifted up, he could feel the tremendous weight being taken off of him, and both him and his cock missed them, Spike’s hips instinctively bucking up into them. But every time she slammed them back down and made them impact his smaller body, alongside waves of euphoric pleasure, he felt tremors making his whole body take the two huge hits.

And he loved it.

If he could get treated like this whenever he got horny, he’d never complain about feeling under-appreciated again. Never.

“Augh! Uhn! Y-Your tits are the best, Twi’! So… Ngh! …Fucking good!” With his whole body flopped back, Spike transcended to a whole new plane of existence as he took what his sibling’s chest was happy to give him, and soon, he felt what should’ve been loads rising up his cock, but were only fat globs of thick, white pre on his tip.

He wasn’t the only one to notice it though.

Stopping the titjob and making her behemoths of breasts go back to weighing Spike down, Twilight stared at the white on his tip like it was something she’d been craving desperately for months now. And it was.

She’d been missing the taste of Spike’s seed ever since he last dumped his loads into her belly, so now, she was going to slurp it all up, and he wouldn’t stop her.

With her chest still in her hands, she started moving the massive things up and down again, but unlike before, these were shorter pumps, not going above his tip and leaving it for her to enjoy. Feeling giddy, and peeping up to Spike just as excited, waiting for her to pounce on it, Twilight didn’t delay, and as she kept using her bosoms to jerk off his oh-so craveable cock, her head dove forward, and after her mouth stretched to wrapped around the beast’s head, her tongue shot onto it, and with his tip inside of her, she hungrily slurped up all the tasty dragon-cum he was giving her.

“Mmm!” A moan escaped her from the taste on her tongue. It was just as thick and lewd and delicious as she’d remembered, and after she swallowed it down, she wanted more!

Continuing to get his cock off with her chest, Twilight’s tongue worked to pleasure his head. With her mouth wrapped around it, her tongue swirled around the head, and somehow, Spike felt the titjob get even better. “Ahn! Nnh!”

Twi’ was treated to a few more globs of rich dragon pre as she went at trying to wring him of his spunk, and she revelled in the addicting taste of every drop she got. She could’ve kept doing this forever, using her mouth and breasts to get him off (she certainly wouldn’t mind staying down here forever) but it was the words that Spike moaned out that stopped her in her tracks.

“Rgh! I’m getting close, Twi’! I-I’m gonna-” Instantly, the mare retreated. Pulling her mouth off of Spike, she immediately pulled her tits from around him too, and after moving back, she left his insanely hung cock throbbing for more, right on the edge of cumming yet stood up, untouched and begging to cum. “Wh-What?”

He looked down needily, and saw her off of his cock, kneeling on the beg before him. He didn’t know why she was doing this, all he knew was that his cock was begging to cum, so much that it was painful.

And who was he to resist his cock’s needs?

Swiftly, both his hands tried to reach down to grab at his dick, just to jerk him off and get him that last extra bit needed to cum…

But Twilight stopped him.

Seeing what he was about to do, her huger hands grabbed his wrists, and as she bent forward, her bare chest dangling down over him, she kept his hands off of himself. “Ngh! Twilight! Please!”

“Nope! I can’t have you cumming just yet, Spike.” Slowly, she released his arms, and watched as he put all his will into not finishing right now.

“Wh-Why?!” He was so desperate though, and even if it wouldn’t be as enjoyable if it wasn’t between her teats, a part of Spike still wanted to cum now.

But Twilight couldn’t have that. “Because…” Her hand grabbed his ankle, and before Spike could do anything else, the huge mare pulled him into the middle of the bed. “I know for a fact that you haven’t had sex with a mare in months, and considering your hands could never be as good as a mare could be, I imagine these balls must be quite… pent-up.” Her hand slipped down to toy with his testicles, and to her delight, she could barely lift them up with one hand. “And I know someplace else you’d be better off shooting all those fat, pent-up loads of yours!”

On the bed, she stood up high above him, and he looked up as her hands moved to the band of her leggings. Twilight was just about to start pulling them down, but then she didn’t. She remembered how much time she had to always spend getting them on and off, relentlessly working to get them over her humongous asscheeks, so she decided not to bother. She didn’t have the patience to do all that now. Instead, forgetting she had magic that could get them off in an instant, Twilight’s hands reached down to the wet crotch of her leggings, and furiously, she tore them open. RIIIIIIP!

They were ripped open for Spike, and though he’d seen how wet she was underneath the clothes, now he could see exactly how desperate her sopping wet pussy was as she showed him it and spread it for him with her fingers. “Ngh! Wouldn’t you rather c-cum in here, Spike? Let my needy pussy get you off instead of just using your hands?”

He could see her dripping with want, he could see how hot and wet her insides promised to be, and most of all, Spike could feel how much his cock longed to be stuffed up his sister’s cunt. So it wasn’t a hard decision. With her above, showing off the big, demanding hole she had leaking between those gigantic thighs of hers, a pleading yet lustful look on her face, Spike nodded gently, gobsmacked, and had to do everything he could to stay patient.

Meanwhile, Twilight’s heart leapt for joy on his nod. It’d been far too long since she’d gotten to ride this gargantuan cock of Spike’s, and she planned to make up for all the lost time.

Excitedly, yet still trying to be sensual enough to entice the dragon further, Twilight and her bare pussy sashayed over Spike and his incredibly immense member as he laid back and let her take the lead. The humongous thing throbbed for her, and Twilight wanted it in her.

Above his hips, without further ado, she squatted down, and Spike watched her muscly yet plush thighs tense as she placed her body over his. The dragon gasped as her hand grabbed his cock, and after she lined it up at her hot, wet entrance, his fat tip able to feel the heat coming off of it…

Twilight moved down and pushed it in.

“HNGGHH! Sweet Celestia! I’d forgotten how fucking big you felt!” It incredible, unlike any other creature’s cock. Only his tip was being embraced by her, and still it was stretching her giant pussy. Holy shit… Spike’s cock again… This is a dream come true!

Spike felt good too, never before having felt anything like what the hot confines of his sister’s cunt were doing to him, but it only got better as she kept sliding down.

“Oh my gosh! Yes! Ngh! It’s so good!” As the mare fed more and more and more of the absurdly colossal dragoncock into her, needing its throbbing girth to widen her hole and showering him with praise the whole way down, Spike could only take it as pleasure was heaped onto him. The titjob was incredible, but this… Nothing could ever hope to feel as good as Twilight’s pussy did wrapped around him.

As he grunted, helplessly accepting every flood of ecstasy that dominated his body, Spike’s toes curled, his fingers dug into the sheets, and he couldn’t help but buck up into the mare, needing to get deeper into her.

“AGH! SPIKE!” Further and further down him she went, and Twi’ revelled in every humongous inch that was shoved up her, until finally she hit the bottom, and sat atop her dragon’s lap as his prick went all the way up to her womb. “AHN! …I-It’s great to know you’re as enthusiastic as I am, Spike, but don’t you think you could be focusing that attention elsewhere?”

Confused, he finally tore his eyes off of their joined parts to look up at her face, but they didn’t make it that far. They were too taken by her fat udders again as she gently swung them from side-to-side, and suddenly Spike understood what she meant.

Meanwhile, Twilight was smiling down at her adopted brother like she wanted to laugh. He looked so adorable with his eyes on her tits, and he looked like he needed them so bad! It was a good thing she’d be giving them to him. Leaning forward, the alicorn stayed squatted, but on placing both her hands on the bed either side of Spike, she moved her body over his, and let him watch both her hanging breasts suddenly move within grabbing distance. “Well? Wouldn’t you rather- AHHN!”

He didn’t let her finish, instead, Spike, captivated by the gargantuan globes placed back in front of him, reached for both her big, purple nipples, and on grabbing them, squeezed hard before one hand kneaded the funbags and the other brought the nipple to his mouth. “Mmm!” His mouth latched onto her, and he sucked and nibbled and made love to her bosoms like he was trying to get milk out of them.

“NGAAH! SPIKE! SWEET CELESTIA! AHN! DON’T STOP!” This was the most enthusiastic she’d ever seen him, but as his assault on her mammaries sent pulses of even more pleasure through her, Twilight didn’t complain, and instead, without warning, began sliding herself back up his meaty pole to finally start fucking him.

“MMM!” Spike moaned around her nipples, now with both of them in his hungry mouth at once, but besides making her moan even more he did nothing to stop Twilight as she slid back up him, and in one forceful smash down, she shoved the entirety of his cock back into her, making his tip crash into her womb again. “MPH!” The weight of the huge mare violently dropping back down onto his hips sent tremors through Spike as his entire body convulsed. With Twilight like this, he was in for a bumpy ride.

He couldn’t wait.

With him going back to work lewdly worshipping her melons, Twilight slid all the way back up him again, moaning the entire time, and again, when she reached the top-

SLAM!

Again, the bed shook with the weight forced down on it, and Spike’s body shook as it was once again battered, but neither cared. They were too busy craving more of what they could give each other, so they gave up holding back.

Or more accurately, Twilight did, and then she started riding him.

In a way that’d make Applejack proud, brutally, the massive mare rode Spike like a rodeo bull, and bounced her entire body up and down on his cock, letting it ram deep into her every time she impaled herself on his gigantic schlong. The bouncing of the bed could probably be heard across the whole castle, and Spike’s hips were definitely going to be sore in the morning, but neither cared.

Twilight’s face looked delirious. It’d been far too long since she’d gotten to have her dragon inside of her, filling every inch of her pussy with his girth and constantly crushing her womb. It was a feeling she’d not gotten to feel in what felt like forever, so while it lasted, she was going to enjoy every depraved second of this.

Meanwhile, Spike still had a face full of her plump, purple pillows and never wanted to leave them. He’d never felt better than he did right now. It was glorious being under Twilight, and even despite the crushing weight she forced onto him over and over again, it was easily worth it for the overwhelming pleasure that was being forced onto him too. He only wished he could see her from the back as she rode him as well, getting the chance to watch her immense asscheeks flail around wildly within her torn leggings.

However, he’d settle with having a face and claws full of her squishy udders, a nose full of the intoxicating, sweaty stench that collected between her teats, and her being full of him.

As they went at it, in a room full of moans, heavy whapping of hips, heavy clapping of cheeks, and their powerful musks combining, it was a miracle the bed didn’t break, or at least it would’ve been if it wasn’t reinforced to be able to handle such a brutal fucking as this one.

Far away, somewhere else in Ponyville, some mares were surely busy looking around in the local gym as they exercised, wondering where in Equestria Twilight was. It sort-of sucked that she had to skip their get-together without even warning them first, but at the same time, Twilight didn’t regret it in the slightest, and she knew for a fact that her friends would’ve done the same if given the chance.

And maybe they’ll get to after this! Up on top of him, repeatedly ramming Spike’s spike into herself again and again and embracing the euphoria it gave her, Twilight couldn’t help but want to share the incomparable euphoria with the others considering it was driving her crazy. Celestia knows they’d love to get to spend ‘quality time’ with Spike again!

She cast aside the thought. For now, she just wanted to focus on riding this cock of cocks. Her friends could have their own turn another time, but now was her turn, and she needed more.

Twilight didn’t hesitate to take what she needed from him.

Time passed as the two fucked. It didn’t matter how much, all that mattered was that Twilight didn’t slow down for even a second, and was determined to wring his cock dry of every last ounce of pleasure she could.Pleasure wasn’t the only thing she was trying to wring out of him though, there was something else she wanted, and she was going to get it very soon.

With her up on top of him, riding his body like she wasn’t at least three times his size, Spike couldn’t hold it back anymore. With his virile body’s new rampant horniness, the unforgettable titjob she blessed him with as foreplay, and now a never-ending supply of his most perverted wet dreams come to life and bombarding him with pleasure, Spike was ready to cum, and the pressure he felt built up was unlike anything he’d felt before.

Pulling away from her bosoms panting, having chosen to stick his head deep into her sweaty, musky cleavage long ago, Spike struggled to get his words out with her her constant pleasuring and pounding, but soon, he managed. “AGH! TWI’! RGH! AH! I’M- UGH! I’M GONNA CUM!”

After the announcement, he truly had no idea what this new-and-improved Twilight would do next. If he thought she’d slow down though, he’d have been sorely wrong.

Like a mare possessed, on hearing his words, Twilight’s speed went from bed-shaking to hip-breaking. She truly held no mercy for him, but still kept sending overpowering pulses of nonstop pleasure through him as she went up and down and up and down in a weighty blur.

One thing was clear: she wanted him to cum. Now. And thanks to her, he was going to.

“AHN! TWILIGHT! I’M…” Using her tits as two huge stress balls to squeeze down on, Spike felt something huge being pumped up from his hyper-sized testes. It travelled all the way up his tense member ready to burst, and with her unrelentingly riding him, it was seconds before the damn broke, and Spike couldn’t hold on any longer as one huge rope of cum blasted out of him and into her cavern.

But that was exactly what she’d been waiting for. The mare was lost in the pleasure her number one assistant could give her as she strived for his orgasm, but when the first glob of cum was shot into her, she knew exactly what to do. In one final, climactic movement, Twilight Sparkle dropped her entire body down onto him and his cock, and with the thing buried as deep in her as she could get it, she let it empty into her, and came then and there as her womb was filled up first, and then the rest of her.

Spike’s climax shook his body like nothing ever had before, and broke his brain. When the first rope shot out of him, it began, and when her pussy walls began squeezing him for every drop he had, Spike was treated to the most mind-boggling orgasm of his life. His entire cock was wrapped in her snug, wet warmth, and in there, the dragon felt as each gigantic rope rose up his shaft to shoot out straight into her womb. And then it just kept coming.

Or rather, he just kept cumming.

Hugging her teats, Spike couldn’t help but moan with Twilight as he kept unloading his fat loads into her. As his balls kept clenching, more and more of his baby batter kept being pumped into Twilight’s womb, until soon there wasn’t enough room for any more, so he kept cumming, and didn’t stop until her belly was bloated with his cum and they were sitting in a small pool of it.

After minutes of nonstop ejaculation, it eventually ended.

“W-Wow, Spike!” With her hands on the big bump of her belly, Twilight could barely believe the amount he had unloaded today. This was hardly the first time he’d impressed her and made her cum so hard it had felt like her brain had turned to mush though, and hopefully it wouldn’t be the last. “There’s… so much of it!”

“Yeah...” He was more baffled than her, the mare having seen it before after all, but he’d enjoyed her being filled just as much as she had, so he wasn’t complaining. He wasn’t complaining about anything in this new world, not getting to fuck Twilight of all mares, not her having the body of a goddess, and certainly not about being her assistant.

If he could stay in this world, he’d never complain again.

“That… was incredible!” With him still lodged inside her, Twi’ got onto her knees, leant forward, and she dropped the entire weight of her chest onto him, crushing the dragon under them.

They were so heavy! He was just about to struggle to escape when he felt her start to speak, him beneath her hugging her huge form, his torso pressed against her bulging belly, and his face lost in between them.

“Did you enjoy it as much as I did?” She could feel him softening inside of her, and again, one of her hands drifted down to rub at her cum-filled belly. “You filled me up so much! You have no idea how much I’ve missed this feeling, Spike.”

There was another feeling she’d missed too.

On her knees, Twilight lifted up her titanic rear, and slowly slid off of his cum-covered pole. It was so thick, so long. She was overjoyed she’d gotten to spend more time with it.

Reaching the tip, Twi’ slipped the last bit out of her, and after his semi-hard member hung half-erect above his balls, she bit her lip and revelled in the feeling as buckets of cum poured out of her to join the pool of it already on the bed. “Mmm!”

After all his seed had eventually oozed out, and made a mess that’d take forever to clean up, Twilight was happy. Collapsing heavily, she dropped onto her side beside Spike to avoid crushing him, and released him from his prison between her hefty hooters.

With her lying next to him on the bed, she hugged him as best she could; only the best for her number one assistant. “So Spike, you didn’t answer my question down there. Did you enjoy that as much as much as I did?”

He had. He really had. “Yeah. It was… awesome.” It did leave him a little worn-out, but it was a small price to pay for that.

One of her hands grabbed him by the junk, and quickly, she slid him up to her so their heads were right next to each other. “Y’know, I never understood why you didn’t want to become an official stud, Spike. I mean, you seemed to enjoy having fun with me and the girls plenty, but then you just stopped.”

Spike had literally no clue what was going through the other him’s mind when that happened, but if ‘having fun with her and the girls’ meant what he thought it did, then he couldn’t fathom what would make the other Spike not want to be a… “Um, Twilight, wh-what’s a stud do again?”

“What? Do you not remember?” Is that why he never wanted to become one? He didn’t fully understand what it was? “If you became a stud, it means it would be your official job to satisfy the… needs of mares. You’d have been paid a ton for it, and I didn’t think it was fair to keep a gift like the one you have all to myself.” She idly fondled him as she spoke, a longing tone in her voice. “I thought it would be the perfect job for you, getting to be surrounded by horny mares alongside still being my personal assistant, but you never wanted to.” Out of nowhere, a hopeful glimmer suddenly came into her voice. “H-Have you changed your mind?”

With one of her huge breasts on top of his chest, him mindlessly playing with its nipple as he thought, Spike didn’t get it. Why the FUCK would the him that used to be in this body not want to get to fuck these gorgeous mares all the time?!

And it wouldn’t be limited to just Twilight! Every mare - including all of her friends -would be his for the fucking! If getting to fuck Twilight just a second ago was a dream come true, then this was something else entirely!

Eagerly, he spoke up. “Y-Yeah! That sounds great!” He couldn’t wait to get to work!

But if he was excited by the prospect, Twilight was over Luna’s moon. “Really?! Yes! That’s amazing, Spike!” Out of nowhere, her hands scooped him up as she rolled onto her back, and after placing him between her bosoms again, Twilight’s hand slipped around the back of his head, and she smushed their lips together.

Out of nowhere, her tongue suddenly dove into his mouth and started swirling around in his mouth, and though Spike had been caught off guard, it wasn’t long before he was enthusiastically returning the favour with his own long, draconic tongue.

If you told him a couple days ago that soon he’d be on top of his sister, making out with her from between her breasts, he’d not have believed it, but now…

Before he could get too into it, Twilight pulled their lips apart. He couldn’t tell what she was doing until her hand reached around her chest and found his flaccid cock. With a dirty look on her face, the mare began stroking it, and Spike couldn’t help it as he felt himself getting hard again.

She spoke lustfully, and with that hungry look in her eye again. “How about, as your first unofficial assignment, we go for a couple more rounds? I don’t know about you but I know I’m not satisfied yet, so d’ya wanna get some early practice in before we head to the town hall to get you signed up?”

He was perfectly content just going the one round, but by the looks of it, the lewder Twilight wasn’t going to give him a choice. So meekly, he nodded anyway, and the instant he did she tossed him back onto the bed.

It was okay, she’d only make work until he did his job and she was satisfied, it wouldn’t take long.

That ‘wouldn’t take long’ was actually seven rounds, and it lasted hours.

Author's Note

The moral of the story is: Holy shit, Maarthul’s art is hot.

Probably my most creatively kinky story idea yet. I can’t decide if it’s leading up to becoming a story or just a sequel, but damn there isn’t enough of this kink out there.

What can I say? Huge dicks are hot, huge tits and asses are hot, put them both together and it’s a party!