Vengeance Is Best Kept In The Family

by Birdybirdbird2

Rating: mature
Tags: Porn, Sex, Fetish, Spoiled Rich, Non-consensual, Diamond Tiara, My Little Pony: Friendship is Magic
Length: 9320

Newly reformed, Diamond still can’t be the pony she wants to be, not with her mother standing in her way. She needs to learn a lesson, and if it takes Diamond giving herself a dick to give her one, then she will.

This fic was a commission for superfun!

Diamond wants to be better, really, she does, but a certain spoiled bitch isn’t letting her. One bizarre collection of events later, and she’s teaching her mom a lesson with her massive futa-cock. Funny how life works, isn’t it?

This fic contains: Futa, incest, foalcon, and non-con that doesn’t take long to become very consensual.

Enjoy!

Art is not mine
Art by shinodage
1938285 on Derpibooru

Published 2025-01-30 22:30:01 UTC
Last updated 2025-01-30 22:30:01 UTC

The Bitch Becomes A Bitch

The Afternoon After Crusaders Of The Lost Mark

“And how dare you even think of speaking to your mother like that?! Do you know how disgraceful you made us look when you spoke back to me like that?!”

Not too long after Diamond Tiara had tried redeeming herself, successfully securing supplies for the schoolyard and making friends with the fillies she used to pick on, while at the same time finally gathering the courage to talk back to her overbearing mother.

It had been incredible! Not only had she finally gotten to be the person she’d always wanted to be, but her mother had walked away defeated afterwards!

She’d never felt elation like finally overcoming her mother.

And then she came home…

“We have an example to make on other ponies! We have to show our dignity, our superiority to them! Are you listening to your mother?!”

“Yes, mother.” Diamond meekly responded back.

Ever since coming back home, this had been going on. Her furious mother had greeted her at the door ‘calmly’, failing to mask the fury she was feeling, and then when she’d made her daughter sit at the kitchen table, she let loose, and screamed and screamed and screamed at her.

That was hours ago, and it was still going on.

What could Diamond do? Make another big speech that would quell her mother’s unending tirade? That wouldn’t work without everypony else there to support her.

So Diamond had to sit here, part of her wishing she’d never stepped out of line while a bigger part of her wanted to start screaming back.

She chose to submit to her mother’s anger. This would end soon…

Hopefully.

“And what did you hope to gain out of it?! Social standing? Money? No! I’m sure all you want is to get all buddy-buddy with those crusader fools! We’re above them, Tiara!”

Diamond was on the verge of talking back, bit her tongue. wouldn’t help her now, not unless she wanted this to go on into the night.

But it wouldn’t have to, as an angel strode in through the door.

An angel that looked a lot like her father. “Honey, I’m home!” After a long day at work, he was returning home.

Dad’s already home? Mother’s been shouting at me that long? Diamond heard Spoiled Rich scoff as her husband entered, not that he heard it. But thankfully, this seemed to mean that their ‘conversation’ had come to a close, and that, finally, it was over, though her mother still looked ready to blow up at her at any second.

“Diamond Tiara, go to your room. You’re grounded for tonight. We’ll continue this tomorrow.” Curtly, she was dismissed, and not wanting to look a gift horse in the mouth, the filly hopped off of her seat and headed for the stairs.

Surely nothing else could happen no-

“And Diamond?”

At the foot of the stairs, Diamond stopped and hesitantly turned around. “…Yes, mother?”

Spoiled raised her head up, looking down on her like she did everypony. “Keep this behaviour up and I may just have to see about driving their families out of Ponyville. It would be a shame if they couldn’t get jobs anymore, wouldn’t it?”

Diamond’s eyes widened. What?! She had next to no idea how the CMC’s families earnt money, but she highly doubted her heinous mom was bluffing. What choice did she have but to comply? “…Y-Yes, mother.”

“Good. No daughter of mine will go shacking up with scum like that. Now go. Your father can bring you up your dinner later.”

Head hung low, she retreated up to her room, with the same part of her still seething on the inside at her abhorrent mother.

No, she couldn’t just give in and let her mother get away with this.

Not this time.

She refused to let it happen.

The rest of the afternoon was as drab as you’d expect. Boredly, Diamond had to start reading some of the many books around her room or working on homework. She wanted toys but her mother didn’t think they were ‘necessary’.

Ugh! Mother... When she went to bed that night, having eaten her food and watched the sun go down, Diamond was still seething, lying awake long after she should have been asleep. It‘s just not fair! Why does she get to be so mean all the time?! And why am I the only foal that has to have her as a mother?!

Her name fit her perfectly. She was spoiled! She didn’t deserve this nice house or to be considered ‘upper-class’. She was the lowest of the low! She was… was a…

She’s a bitch! That’s what she is! Diamond didn’t know exactly what that word meant, but when it was referring to her mother, it just felt… right. Yeah! She’s just a stupid bitch who shouldn’t get to treat others like she does!

She’d always been like this, for as long as Diamond could remember. Her mother had always been the high and mighty, holier than thou bitch that turned her upturned nose on others. And why? Because she thought of herself better than those poorer than her.

It wasn’t right. She didn’t get to treat the crusaders like she did! She didn’t get to treat her like she did! It wasn’t fair, and it was about time somepony did something about it.

And that pony was going to be her!

Though she didn’t have a clue how, Diamond Tiara was determined now. No matter what she did, how big or how small, she was going to get back at her mother, showing her that she didn’t get to treat others like that. And who knows, maybe when she understood what it was like to be mistreated, then she’d become nicer!

It was worth a shot!

But now there was the matter of what to do…

What doesn’t mother like? What does she hate? The daughter could probably write a book on every single thing that her mother hated, but that wasn’t enough. She didn’t just need something she hated, she needed something she despised, she loathed and something she-

“Absolutely not! Never in a million years!” Her mother’s voice cried out from her bedroom, like a hoof on a chalkboard.

Ugh! What’s mother complaining about now? Bored and wide awake, it wasn’t long before Diamond was curious, so making up her mind quickly, she slipped off of the bed and made her way to the door. It’s probably something stupid…

At the door, Tiara couldn’t hear what was happening. Her parents’ voices were too muffled to hear when her mother wasn’t screaming her lungs out.

But what was stopping her from leaving her room to hear them? Her being grounded? It being past her bedtime? She was already rebelling against her mother, so what was one more misdemeanour?

With a little thrill at the idea of disobeying her bitch of a mother again, Diamond’s hoof turned the doorknob as silently as she could, and upon easing the door open, the mare crept out into the hall, attracted by the light coming from her parents’ bedroom like a moth.

Their door was ajar, so if she wanted to peek on them, it’d be effortless.

So she did. On sneaking her way over there, she reached the door, and took a look inside.

What she saw stunned her.

On the bed, lying on her side reading a book, was her mother, and beside the bed, stood up, was her father. What shocked her though was that her mother looked revolted, and her father had something brown and long sticking out from between his legs.

What is that thing? Diamond didn’t get to think on it long as their conversation continued.

“Spoiled, c’mon, how many years has it been by now? Stallions have needs…” The most vulnerable she’d ever seen him, Diamond’s father, Filthy Rich, looked pleadingly at her mother, but she didn’t seem so empathetic.

“Good for you, now shut up about it. I let you stick that disgusting thing in my marehood once before, but if you think it’s happening again, you’re wrong, Filthy.” The harsh mare held nothing back from her husband, but Diamond Tiara was far from focusing on his begging face.

He stuck that thing of his inside her marehood? Why? That wasn’t the only thing Diamond was interested in. What she found just as intriguing was the look on her mother’s face; she’d never seen her so repulsed, so disgusted by something. And why was her father’s gaze lingering on her mom’s butt?

For obvious reasons, she wanted to know more.

Her dad’s voice kept going. “But why not? It was a little fun last time, wasn’t it? What if you enjoyed it too-“

“Filthy.” Spoiled levelled the death glare of death glares at her husband. Her thin patience had run out, and clearly, she was done with listening to him. “Let me make something clear for you: I. Don’t. Want. Your. Disgusting. Little. Cock. In. Me. The only reason I allowed you to defile me once before was to procure an heir, and now that Diamond’s getting all bratty, the last thing I need is to hear about you being horny and unable to deal with it.” As if losing interest, Spoiled’s gaze turned back to her book.

She tried leaving the conversation there, but Filthy didn’t want to. “But-“

The bitch interrupted him. “I know about those mistresses you’ve been seeing. If you’re that pathetic then just go to them and stop bothering me.” The stallion looked defeated, but of course she had to add one more thing. “And don’t you even think about sleeping in this bed tonight. I don’t want you trying anything.”

He’d been doing that most nights recently, sleeping downstairs on the couch, and it looked like he’d be doing it again. Head hung low, Filthy gave up, and with one more glance at his wife, he headed for the door.

Uh oh! From her vantage point, Diamond spotted her father creep ever closer and closer, so she did the only thing she could think to: running the fuck away.

The last thing she needed to do was get involved when her mother was this irate, so she scarpered, and sprinted hurriedly off back to her room, screw how much noise she made!

But fortunately, everything turned out just fine. When Diamond returned back to her room and shut the door as quietly as she could before diving into her bed, Filthy didn’t suspect a thing. He probably had other things on his mind.

Regardless, she heard him trot straight past her room and down the stairs. She was in the clear.

The filly released the breath she’d been holding in, and turned to stare at the ceiling. She was still going to go through with her plan. Heck, after how she’d treated her father too, being so mean to him and making him sleep on the couch again, the bitch definitely deserved it.

And so, Diamond Tiara’s mind returned to all she’d seen in her parents’ bedroom. All of it.

Now, despite being pretty young, the filly wasn’t an idiot. She knew colts had different things between their legs than fillies, it was pretty hard not to notice when nudity was the norm, but still… she’d never seen that before!

She thought mares had their ‘vaginas’ right beneath their butthole while stallions had these two ball-like things. But no! Apparently stallions also had ‘cocks’? And they put them in mares? Where? And why?

All Diamond knew was that her mom absolutely HATED the idea of a cock being put inside of her more than anything else, so it’d be the perfect way to get back at her!

All she had to do now was figure out a way to make it happen… somehow.

Oh well! She could think about that tomorrow,it was a school day, but after school she was free to go wherever she pleased, so rolling over in bed, Diamond closed her eyes and tried drifting off to sleep.

She had a busy day tomorrow after all, and she had a pretty good idea on where to go!

The next day came soon enough, and Diamond leapt out of bed early in the morning, eager to get to showing her mother a lesson.

Unfortunately though, school came first.

With her saddlebags filled with all her school supplies hung on her back, she made her way downstairs, and after breakfast, she was ready to face the day head-on!

Then somepony stopped her. “Diamond Tiara.”

Nervously, the fillies head rotated to spy her mother’s insufferable expression. “Yes, mother?”

The mare spoke like she owned the world, and as if her grating voice was a gift to hear. “If you remember what I said yesterday then we won’t need to have another talk. But remember: if you make me look bad by spending any time at all with those low-lives, I will make both your life and their’s Hell. Got it?”

Of course she remembered, and admittedly, a little of the wind was taken out of Tiara’s sails. Shrinking, she responded. “Yes, mother.”

Her response seemed to please her, and the bitch even seemed a little proud of herself. Not her, of course. “Good. Then you are dismissed.”

The filly left, but still filled with the determination to once again put her snide mom in her place.

The day went without incident. The school day began, dragged on like usual, and then ended when the final bell rang.

Well… One thing did happen.

It was lunch, and Diamond Tiara was walking alone through the new and improved schoolyard, brooding. Every now and then, a foal or filly would call out to her, in which she’d nervously respond with an awkward wave or a stuttered reply, but then, they arrived.

“Heya Diamond! Wanna come hang out with us?” Her head snapped around, and it greeted the three fillies she’d been picking on for months.

First of all, they were being super nice to her. This wasn’t too much of a surprise; they’d always been nice and kind, even to her, only making her regret her actions more.

But what made her freeze at their arrival was her mother’s words still ringing in her head: ‘If you make me look bad by spending any time at all with those low-lives, I will make both your life and their’s Hell. Got it?’

She couldn’t hang out with them.

Sure, her cruel bitch of a mother wasn’t here, but if word somehow got back to her…

She couldn’t let that happen, so it would be best if she just didn’t hang out with them at all.

Awkwardly, she raised an apologetic hoof. “Oh, uh, sorry guys, I… umm… Maybe another time?” It was the best she could do. She couldn’t just tell them ‘no’! Wasn’t she their friend now?

Luckily, they didn’t seem to mind too much. “That’s fine! If ya ever wanna come hang out though, you know where the clubhouse is!”

“Yeah!”

“We’d be happy if you ever wanted to come by.”

Their being so nice… It’s not right for mother to treat them so terribly. This whole conversation only strengthened her will. One day she’d get to play with them and hang out like they always do, but for now… “Sure. I’ll… do that.”

That seemed to placate the ecstatic trio. “Okay then! Anyway, see you later, Diamond!”

They trotted off happily, and the pink filly could only watch unhappily as they left her behind. “…Bye.”

Oh, she was definitely getting back at her mother for this. And while she was at it, she’d get her to leave her and the crusaders alone too!

She could do that… Probably.

Other than that, the school day was as boring as ever, and it was over before Diamond knew it.

RIIIIIIIIIING!

When the abrasive bell blared in the students’ ears, the filly with a plan didn’t hesitate to snatch up her saddlebags, and right after they were dismissed she bolted out the door.

With the other foals watching her confused, she dashed off into the distance in a straight line to her destination. She knew exactly where she wanted to go.

And minutes later, with her lungs panting and her little legs burning after the constant, nonstop sprinting, she arrived.

It was the one, the only, the library (otherwise known as the Castle of Friendship ever since Golden Oaks got destroyed).

Without hesitating, Diamond stepped up, raised a hoof, and knocked on the door. The filly would need to be quick if she wanted to be home without her mother noticing she’d come here.

And fortunately, a little dragon came to her rescue as he promptly opened the massive door.

“Hi. I’m here to check out some of the books. Is the library still open?” Despite reading being one of the only pastimes her mother let her enjoy, alongside picking on those ‘beneath her’, Diamond was hardly a regular here. That bitchy mare chose all of the books she read, not her after all.

Meanwhile, Spike glared at the former bully suspiciously, but soon shrugged. Even with his suspicions, Twilight would kill him if he refused letting an interested filly see their publicly-available library, so he instead let her in and led her on the short walk to where she wanted to be.

Diamond marvelled at all the books on display here. Some she’d read but so many others were tomes full of the unknown.

There wad bound to be something here that could teach her mom a lesson!

“Take whatever books you want, just make sure they’re back in a couple weeks.” Dismissively, Spike strolled off, and left Diamond Tiara to her own devices, for better or for worse.

So she didn’t hesitate. Like the vengeance-fueled filly she was, the rebellious mare strode on over to the nearest shelf of books on books on books, and she quickly started going through them one by one.

All of them.

Every single one.

As she strolled down one humongous bookcase, her eyes scanned every last cover, looking for something, anything that would work. But alas, Twilight’s collection was far from helpful.

Sleepovers 101… The Tale Of The Love Potion… Supernaturals: Natural Remedies That Are Simply Super… None of these were helpful! She wasn’t looking to have a sleepover, she didn’t want her mother to fall in love with her, and she definitely didn’t want to cure any ailment (not unless her mother’s bitchyness was a clinical condition).

All these books seemed to be a bust…

By the end, Diamond had gone through what felt like hundreds and hundreds of books, but none of them had anything that would’ve helped teach her mother a lesson! She wasn’t any closer to finding what she wanted.

She’d failed…

Or had she?

After checking one last shelf, one as useless as all the others, Diamond hung her head low, with the sigh of all sighs escaping her. Glumly, she climbed down the ladder she was on and turned to leave, but only to spot a stack of books on the table.

She hadn’t looked through those ones…

Curiously, and with one final ember of hope reignited in her, Diamond trotted over to them.

They were all in a neat stack, with a tiny note over them. The filly couldn’t help but be interested. Why are these ones over here? They don’t seem damaged or anything. Hoping to find the answer to her question, she peered at the note.

In pretty handwriting, it said:

‘Spike,

Could you take these down to Twilight’s bedroom when you have time? I was going through the books and these ones don’t seem to be very appropriate for a public library.

Thanks!’

It continued on in much messier handwriting.

‘This note was written with the supervision of The Great and Powerful Trixie! Performing at Ponyville Town Hall all week!’

Diamond Tiara ignored that last part. Her curiosity was piqued though. What books wouldn’t be ‘appropriate’ for a public library? The kind that she could use to get revenge on her mother with, perhaps?

With a devilish smirk, one similar to the one her mother loved to wear, Diamond gladly began looking through them, and as soon as the note was removed, the mare was beyond intrigued.

The first book immediately stuck out to her, mainly because of its rather risqué cover. It showed a mare and a stallion, ones doing much more than cuddling with the way she was sat on his lap and clearly moaning. Above it, text read ‘The Karmaresutra’. Diamond didn’t have a clue what that meant, but some interested part of her longed to take it home.

Moving it to one side, she read through the next. Text said ‘The Art of Domination’ with a whip beneath it, alongside… some big wooden thing. It kind of looked like a paddle. Was this book about slavery or something and it was too dark to be kept in the library? Diamond didn’t know, but she put it with the other and looked at the last one.

‘A Pony’s Guide to Perverted Potions’ it said. What did ‘perverted’ mean? The potions part however did entice the filly, maybe one of them would be able to make her mother nicer, or be able to get back at her somehow. Diamond hoped.

With her mind set and a thrilled grin on her face, she snatched up the note, and after stuffing it into her saddlebag, she took the three ‘inappropriate’ books too and hid them away in her bags.

She had what she needed, hopefully, so now she just had to leave, sneakily. If Spike was supposed to get rid of these, then she probably couldn’t request to borrow them, so theft was the only option.

But surely she couldn’t just steal from a princess’s library!

…As it turned out, she could.

Nervously looking around the entire time, Diamond Tiara waltzed out of the castle the same way she came in, and without being noticed by Spike or anypony, she made it into the town with her stolen goods without being noticed.

She was a thief now, with stuff that she shouldn’t have had…

It’ll be fine… What could go wrong? She’d just stolen some inappropriate things from a princess… I just need to get back home and-

Home.

Home? She couldn’t go home! If she came back to the house with some new books she’d gotten from the library, her mother would absolutely want to know what she was reading!

She couldn’t take these home! What if her mother found out about her plan to get back at her?! She’d be grounded for life!

Home was a no-go. But where else?

School? Definitely not. If these weren’t appropriate for a library, she doubted Cheerilee would accept her keeping them there.

She only had one option, one option that terrified her just to think about.

“Heya Diamond! Didja wanna come hang out with us?” Apple Bloom called from up above, and beside her, the other crusaders were smiling too.

It was the clubhouse. Of course it was the clubhouse. Where else could she go in her time of need?

Despite the risk of being around them, she had to be here if she wanted these to be kept somewhere safe. Maybe I should’ve thought about this plan a little more before taking these…

There was no going back now, so Diamond gingerly smiled back up at them. “H-Hey guys, and… kinda.”

Like the welcoming hosts they were, the CMCs ushered her inside, and soon the trio were sat listening to her as she sat with them, elaborating on her plan for revenge. “And so in order to get revenge on my mother, I need these books, but this place is the only place I know where they could be kept safe from any other ponies. So, can I keep them here?” It felt nice to have friends to properly vent her problems to. Maybe soon she’d get to spend time with them without having to worry about her mom somehow knowing she was here and ruining their fun.

As excited as Diamond was though, the CMCs didn’t look so sure. “We’d be happy an’ all to help ya out, Diamond, but are ya sure revenge is the right way? Remember what happened wi’ Babs?”

The others seemed to agree, but Miss Tiara didn’t. She really didn’t. “Yes. I’m sure. You all know my mother, and you all know how terrible she can be. Sometimes you can only fight fire with fire.” With her head stuck up like her mother’s always was, she finished, and the crusaders glanced at each other nervously.

Eventually though, like they’d been having a silent telepathic conversation, the council of cutie marks came to their decision, glancing back at their former bully seemingly convinced. “Fine then. We’ll help you get back at your mom because you’re our friend now… also your mom sucks. But don’t go giving us the blame if your books ever get found, Diamond. That’s not cool.”

A smile burst onto Diamond’s muzzle, and she happily agreed to their terms.

Now she had a safe place to keep them and read them!

Perfect!

Half an hour later, the four were still in the clubhouse, and the four were now doing their own things: Apple Bloom was looking for future potential ponies for the CMCs to help, Sweetie Belle was practicing a spell on a plant pot, Scootaloo was trying to successfully perform a scooter trick she’d seen, and Diamond was… in the corner.

Separated from them, she was intent on reading one of her three new books, but was struggling to choose one to start with. I mean… that ‘domination’ one could help me stand up to my mother better, but the potion one might have a helpful potion in it… and the Karmaresutra…

It was a tough choice. All of them interested her in different ways, but eventually, she had to choose one.

I’ll go with… She thought about what she wanted the books for. She originally wanted them to get back at her mother, so if she had to choose one, it’d probably be… This one!

Her hoof landed on a book, and she made her decision.

She would read ‘A Pony’s Guide To Perverted Potions’ first. There had to be a potion in there that’d help her, right?

There was only one way to find out. Diamond opened the book.

Immediately, she was greeted with the contents the tome held, and was introduced to myraids of potion recipes. Well… I need to start somewhere.

The filly began at the first potion, and then started going through them.

Buxom brew? What did that mean? Intrigued, she kept reading. This potion will greatly increase the proportions of a mare, giving her wider hips, a larger behind, a fuller ponut, and bigger teats…

That… didn’t sound like what she was looking for.

She moved onto the next.

Lactation Tonic… In mares, this potion will rapidly increase milk production, whereas in stallions, it rapidly increases cum production. The effect lasts for two hours.

Huh? What was ‘cum’? Regardless, it also didn’t sound like what she was looking for, so Diamond Tiara moved on.

And the next was the Futa potion? What did ‘futa’ mean? She was about to find out. This potion will transform the drinker’s genitalia (as long as they have female genitalia) into the genitalia of a stallion/a horsecock.

…That could work. A horsecock was that thingy her dad had last night, right? The diagram certainly made it look like that. If so, then this potion might be exactly what she was looking for!

Not giving her mother one, no, though her mother would probably hate that. But she told her dad just how much she didn’t want him to ‘stick his cock’ inside of her…

What if she did that? If she got a horsecock and stuck it in her mother, then maybe she’d be able to be mean to her just like she was mean to her friends!

It was the perfect plan!

Suddenly enthused, Diamond rose to her hooves, turning to the crusaders. “Alright, girls! I need your help with something!”

They were more than happy to help (plus, they seemed a little bored). Either way, she had their assistance now. “Sure, Diamond. What do you need our help with?”

She dropped the book onto the floor and slid it over. “We need to find those ingredients for a potion, then I’m gonna use that to get back at my mother!”

Apparently boredom overrode their morality, because they were instantly on board! “Yeah!”

“Let’s do it!”

“This’ll be fun!”

They each chose their ingredients, and then, the four headed off to spend the rest of the day gathering them, missing the message in the book detailing how permanent this particular potion was.

Hours passed, and in that time, plenty happened. The crusaders were sent out to their individual tasks, succeeded, and then they all reconvened back at the clubhouse were a potion was to be brewed.

And a potion was brewed.

With Apple Bloom’s apparent potion-related knowledge, roughly an hour was spent brewing a potion, an effort in which many laughs and jokes were shared.

But eventually, it was over, and the sun was beginning to fall.

“There’s yer potion, Diamond! I hope it works ‘n all!” What Apple Bloom handed her was a small bottle, one with a lightly glowing pink liquid inside, and Diamond Tiara quickly stashed it in her saddlebags, with her books not coming home with her.

“Thanks for this, girls, I really appreciate the help. Maybe my mother will let us hang out together after this!”

“Yeah!”

“That’d be great!”

Hopefully she would. Having friends… it was great! And yet she’d had to feel nervous every second she’d spent with these three.

But she’d be putting an end to that soon!

After waving them off, Diamond headed back home, and was ready to teach her mother a lesson.

That’d put her in her place!

Diamond didn’t know what to think then she entered her house late at night, but a few things did occur to her.

Firstly, yes! She was this close to enacting her little plan! She couldn’t wait!

Secondly, her mother. She’d entirely forgotten about both her and the time when she’d hung out with the crusaders! And if she was spotted, then what about the third thing?

Third being: the potion! If she was spotted by her mother, she’d definitely be going through her saddlebags, and if she found the potion…

There was a lot to worry about, but thankfully, when Diamond snuck into her house late, she found an empty room and crept in.

Maybe nopony noticed she’d not come back from school?

Praying she wasn’t spotted, she immediately snook up the stairs, and as quickly as her little legs could carry her, she speedily and stealthily made it to her room, charging in and diving onto her bed.

She was safe, and on her bed, she slipped the potion out. That was safe too. All according to plan!

The door opening wasn’t the plan though, yet it happened anyway, and barely gave the filly enough time to stuff the mini bottle under her blanket.

When her head snapped to the door, thankfully, her antics had gone unnoticed, and her mother walked in with a very displeased frown on her annoying face.

Uh oh. She didn’t look happy.

“Diamond Tiara!” Her grating voice screeched out, regardless of how late it was. “Just where do you think you’ve been?! You better not have been with those crusaders!”

Racking her brain, Diamond forced herself to come up with the best excuse she could. What would her mother want to hear? “Oh, mother, I was… at the library. I just got lost in seeing all the books they had and wanted to go through them all.” Please believe it. Please believe it. Please believe it.

She didn’t seem to. “Oh? And just where are these books, Diamond?”

Of course, she had none. She racked her mind again. “I didn’t want any. None of the ones I could find were as good as the ones you get me, mother.” Flattery, that would work, surely.

And it did. Though she didn’t look pleased, conveniently, Spoiled Rich left it there. Diamond’s prayers were answered. “Fine. But just know that I’ll be going to Princess Twilight herself tomorrow to prove your little story.”

“Okay, mother.”

After a second of silence, the bitch spoke up again. “Now get to sleep. We need our beauty sleep if we want to look as good as we do, you know.”

“Okay, mother.”

Nodding, finally satisfied, Spoiled turned tail and left, shutting her bedroom door so Diamond could release the biggest sigh of her life.

Thank Celestia, that was close! It’s a good thing she didn’t notice this… Cradling the potion in her hooves, Diamond eyed the elixir like it was the most precious thing she owned.

And maybe it was. It would finally put an end to her mother’s tyranny. This, this would finally put her in her place and punish her for all her wrongdoings. This would finally let Diamond give her a taste of her own medicine. And maybe then, when she’d seen what it felt like to be treated so wrongly, then maybe she’d be nicer.

Diamond couldn’t wait to drink it.

Literally.

Nothing was going to stop her from drinking it now, and finally turning her life around!

Okay, here goes nothing! Making her mind up, Diamond Tiara raised the bottle to her lips, and after readying herself, tipped the bottle up and let the magical liquid travel down her throat and into her stomach.

She chugged it, not letting a drop go to waste. It didn’t taste bad; quite nice, actually. And soon, before she knew it, the bottle was empty, and she was pulling it away from her mouth.

She waited for something to happen… and nothing did.

What?! Why is nothing happening? Isn’t- “Hurgh!”

Then, all at once, something did happen, a powerful, intense, magical feeling down between her legs.

Rgh! Ah! Is it… working? It definitely was, and she got to watch it get to work remodelling her privates.

As she stared down, awestruck, the filly watched her minuscule teats shrink into complete nothingness, and they were far from the last thing to go. The puffy lips of her marehood didn’t vanish, but were repurposed into building a stallion’s sheath at her nethers, with her insides already working to replace the unneeded cavern inside of her and her useless womb.

Then came everything else. Her little clit had only grown, and while it did it was reshaped, reworked into the same tool every stallion had stored inside of him. But the creation of her cock-holder didn’t distract Diamond from the growing weight under it, and it was pretty hard to miss the two fat and hefty testicles she now had anyway.

But when the growing and growing was over and done with, and Diamond Tiara saw the change between her thighs come to a stop, all that was left was a painful tension, like something wanted to escape her.

The filly couldn’t hold it much longer, so gritting her teeth, she released it and-

And her humongous horsecock was pushed right out of her sheath and into the open.

WOAH! She stared at it for a second in awe, and before she knew it, the grin of all grins grew on Diamond’s pink muzzle. It worked!

Indeed it had! The potion had worked fantastically! It looked just like the one her dad had, long and veiny and throbbing, only with two major differences: one, hers was pink, and two, it was HUGE!

It was definitely bigger than her dad’s, and by the looks of it, the sack underneath her sheath was bigger than his too!

Would her mother love it or hate it more because of this though?

Either way, Diamond couldn’t wait to show it off to her!

…She didn’t expect it to feel this weird though. Every time it throbbed and it twitched without her wanting it to, pulses of… something hit her. It was like pleasure, but it was painful too, like her cock wanted something and she didn’t know what.

It sucked! She wanted to make the throbbing stop and stop it from feeling so… so impatient, but the filly hardly knew how on of these things worked.

All she could do was do what she’d planned to do with this thing, and after that, then she’d figure out how to stop it.

Okay… Time to go see mother. The nervousness came back to Diamond all at once. Was she really going to confront her mother? Could she? Would she even succeed or would she catch on and just become even worse?!

…Things couldn’t stay how they were.

Her bitch of a mother was ruining her life, so making up her mind, Diamond Tiara jumped off of the bed, and with her massive futa-cock beneath her, she strode on over to her bedroom door.

Tonight was the night that things were going to change!

Out of her room, into the hall, and down it to her parents’ bedroom. As stealthily as she could, she made it, and was ready to make sure all her hard work in getting this thing wouldn’t go to waste.

It was weird having this, and not just because of the irritating throbbing it kept doing. No, it was the bobbing beneath her too. She could feel it, feel every inch of it, and yet, she couldn’t control it.

It was weird, but things were about to get a lot weirder.

Taking a deep breath and readying herself, Diamond Tiara gently opened the door to her mother’s room.

The first thing she saw was a half-filled bed. On one side was her mother, and on the other… Dad must be sleeping downstairs again. That was good for her at least. And on that bed, lying on her back like she always did and snoring loud enough that it was a surprise all of Ponyville couldn’t hear her, Spoiled was sleeping soundly, oblivious to the fact that her daughter had given herself a big, bad horsecock right after she’d left.

The mare was also oblivious as to what her daughter planned to do to her with it tonight.

Pushing the door shut and not even bothering to close it, Diamond crept forward, with her member still pulsating demandingly. Not much was going to get done down here on the floor though, so the filly made the effort of clambering up onto the foot of the bed.

And so, she was on the bed and her mother’s prone form was before her. In all honesty, she had no idea how she was going to do this. She doubted her mother would just let her do this considering her hatred of it was why she was doing it in the first place…

Eventually, Diamond took a deep breath, and made her decision. She crawled under the blanket. Trying to ignore the feeling that her cock against the bed sent through her, Diamond made it over to her mother, and then, she rose, lifting the bed covers off of her mother but keeping them over her.

The filly was right between her mother’s legs now, with her fat cock directly on top of the mare’s large tears; she was right where she wanted to be.

Meanwhile, Spoiled noticed that the blanket had been taken off of her, she’d noticed quickly, and so she was unpleasantly forced up. “Urgh… What…” Waking up with a sneer, the bitch immediately assumed her husband had taken the blanket again, only to look down and spy… What in Equestria is… She let her eyes adjust, and then she saw what it was.

It was her daughter kneeling on her bed between her spread legs, but between Diamond’s legs, there was something that made Spoiled’s eyes widen to the size of saucers.

Her daughter had a dick. Not just any old stallion dick like the one her husband had though, she had a beast of a cock, one throbbing powerfully as it lied right on top of her big, milk-filled teats.

Spoiled wanted to respond, but for the first time in what felt like forever, she was without words. “Ah… Wha… I… Bu…” Sh-She has a… Diamond has… It’s…

With her mother purely gobsmacked by her new appendage, the filly took this chance to speak, gathering all her courage before she finally began. “Mother, you once said that all bad fillies need to be punished to learn right from wrong. Well, um, n-now it’s your turn.”

Even though her confidence dwindled nearer the end, Tiara still pushed forward. Metaphorically. In reality, she pulled her hips back, and slipped her cock off of her mother’s bosoms before lining it up at her entrance.

Then and only then, Spoiled Rich returned back to reality, just in time to watch as her daughter reared her hips back and shoved forward.

“Diamond! Wh-Where in Equestria did you get aUUUGGGGHHNNN!” Spoiled’s sentence was cut off as the fat tip of her filly’s brand new cock forced its way into her, and all of a sudden, feeling she hadn’t felt for years coursed through her, only much, much stronger. “Aughn! Uhh!”

The bitch was utterly perplexed. She woke up groggily from a night like any other, only for…

Wh-Why is my daughter- “Ughn!” Why is Diamond Tiara doing this to me?! And where the f-fuck did she even get that thing?! And why is it so massive and feels so… She had no clue, literally not one, but she didn’t get to theorise before a familiar foal started bucking into her. “NGGUGH!”

Looking down, she saw her daughter, but not the one she knew. This one had a massive dong between her legs, and her face was that of pure, pleasurable joy. It looked like she was more than enjoying herself down there, and she was. Oh my gosh! This is awesome! Mom feels so good! Diamond now understood why her dad had wanted this: this was the best thing she’d ever felt! It was like her cock was getting a big massage, that or a big, tight hug that was squeezing down on her. Either way, it was awesome!

She couldn’t wait to keep going!

“Ngh… D-Diamond… Aghn! Wh-What do you think you are you doing?!” To her horror, the filly appeared to be energetically bucking deeper into her depths, but Spoiled didn’t stop her. Not only was the pure shock of her daughter fucking her still affecting her, but something else was too: the fat cock being shoved into her tight snatch.

To her disgust, she was enjoying this a little.

…Or perhaps more than a little considering how ridiculously wet she was getting. Either way, Spoiled kept moaning.

And Diamond kept bucking, thrusting back and forth eagerly again and again to get deeper and get more of her mother’s body wrapped around her length. As she indulged in incest though, she did her best to answer her mom’s question. “You’re always so mean to me and… Ngh! Ahn! Heck! Y-You’re always so mean to me and the Cutie Mark Crusaders! Ah! It… It’s not fair! So I’m teaching you a lesson! Angh! Agh! An-And it feels really good!”

As much as Spoiled wanted to stop her, she didn’t. She had to, not only was her own daughter working hard to mate her own mother, but she couldn’t just let Diamond get away with this either! She needed to discipline her for rebelling against her! However, at the same time, the filly wasn’t wrong.

It felt really good!

So Spoiled never moved, instead she just laid there and took it like a whore, ‘learning her lesson’. Uhhn! Ugh! I don’t remember sex feeling so good… This is…

Don’t get her wrong, it was still awful, getting ravaged and used like this by her own flesh and blood with a disgustingly massive cock, but at least she could take comfort in the fact that she wasn’t enjoying it, and that Diamond would get her deserved punishment after this when it was over.

That’s what she thought, but the wetness between her legs and the moans coming from her mouth said otherwise.

And speaking of actions going unpunished, a look of pure elation covered Diamond Tiara’s face as she hilted herself in her mother. She didn’t even know what a womb was, and yet her tip was shoved against her mother’s. “NGHHHHHH! Mom! You feel so good! Ahhn!” The push in hadn’t been too difficult. Her mother had been tight considering her hole didn’t get much use, but with how wet she’d gotten, and how much slippier her hole had gotten, Diamond hadn’t had a hard time.

And she wouldn’t have a hard time fucking her from here on either.

Unable to push any deeper, Diamond did what her instincts demanded, and she pulled her little hips back, sliding herself out.

When girthy inches of her cock were no longer in the snug confines of her mother, she knew there was really only one way to go. So she shoved herself back in in one big thrust. “NGAAAUUUGGHH! MOM!”

“UNNGH! AUH! GUH!” For the first time, Diamond noticed that she wasn’t moaning alone, with their voices joining in a choir of taboo depravity. Her mom was moaning, just like her, with her usually irritating voice sounding… slutty, not that the foal knew the word.

But it revealed something to Diamond: she was enjoying this too!

What?! She- Auhn! Sh-She’s not supposed to be enjoying it! She’s supposed to be humiliated! Even knowing this though, it wasn’t enough to stop her hips from moving back and forth. She was now an addict to her mother’s body.

That didn’t mean she couldn’t use this to her advantage though…

With a plan, the fat-cocked filly made her choice and - using all of her willpower - she pulled back another time, but this time enough to make herself entirely leave her mother’s wet grasp.

She dropped her slickened cock down onto her mother’s teats and looked back up at her, only to see her desperate, disappointed eyes looking back. The bitch clearly wanted more, even if she wouldn’t say it.

So Diamond made her proposition, trying to ignore her throbbing cock that didn’t appreciate getting its pussy-plowing interrupted. “Ngh… Alright, Mom, you want my cock more, right?”

The bitch clearly struggled to answer, before eventually coming out with an indecisive “…N-N-No!”

It was obviously a lie, so Diamond kept going. “Well, I-I’ll only keep giving you it when you promise you’ll stop being so mean to me and the crusaders. Deal?”

Before her, the mare clearly struggled. She couldn’t just let her daughter run amok in her life hanging out with those lowlifes, but at the same time…

She needed more of that fat, girthy, humongous, studly cock in her.

So she kept struggling to answer, gritting her teeth, all while the feeling of emptiness inside her cunt only grew, alongside her desperation.

What choice did she have?

“…Fine.” The mare grumbled.

“Huh?”

“I-I said fine! You can hang out with those… crusaders from now on…” She hated to say it, but she needed more at this point.

“Really?!” Meanwhile, Diamond had stars in her eyes. Her plan had worked! However… “Are you sure you aren’t going to go back on your promise?”

Spoiled’s patience snapped. Getting up off of her ass, she flipped over, and with her head down, she stuck her flank back for her daughter, lifting her tail high and presenting herself like a mare who wanted their stallion to mount them. “Yes! Fine! Hang out with whoever you want! Just keep fucking me silly!”

Diamond stared in awe at the fat rump shoved out at her. She’d never noticed before, but she loved how… chubby it looked, how the big pink asscheeks jiggled in place from the slightest movements. At her waist, the filly felt her cock throbbing harder. It looked gorgeous, enticing. If she knew the word, she’d call it fuckable.

Putting her hooves on each of her mom’s big flankcheeks, Diamond couldn’t wait to finish what she started. She stepped forward, put her tip at the winking entrance, and then-

“AUUGHN! Yes, Diamond! Rut your mother!” With the plush, squishy softness of her mom’s pudgy asscheeks beneath her hooves, Diamond bucked back into her, making her rear jiggle some more as her hips struck it eagerly.

“Ahhn! Mom! Ngh! Rgh! AH!” Unlike the first time, a dicked-up Diamond had no problem bucking her way to her mate’s womb. In one excited thrust, her hung horsecock barged all the way into Spoiled’s welcoming depths, and didn’t stop until it kissed her deepest point, caught in the mare’s hot, wet embrace yet again.

And then, Diamond pulled out, and she thrust forward again, and again, and without a care in the world, she started fucking her mother like there was no tomorrow.

Before any time at all, the room was flooded with the sounds of a sloppy rutting, of a cock slipping in and out of a pony’s sopping wet slit while the two mares indulged in the taboo and moaned like they wanted all of Ponyville to hear.

In. Out. In. Out. The pair hardly expected their night to go this way, but neither were complaining.

It was as if all the arguments and disobeying between them had never even happened. Now, in Spoiled’s bed, they were just lovers, one giving the other their all and the other on the receiving end of such massive meat.

It was astonishing to think that only an hour earlier, they’d been completely different ponies. Diamond had been a filly like any other, and now she was a virile futa-stud. Meanwhile, Spoiled had been a mare set on abstinence, and now she was a whore and an addict to her daughter’s fat schlong.

They’d come so far.

And speaking of cumming…

After so much relentless pounding, after Spoiled felt her filly’s hips smack into her behind over and over and over again, getting pleasure forced through her as her ass shook and her teats swayed, she was getting close, and so was Diamond.

“NGH! MOM! I CAN FEEL SOMETHING IN MY COCK!” It was like rising pressure in her dong, she could feel something getting stronger and stronger, like the feeling was going to burst, and for some reason, though she didn’t understand why, she wanted to burst inside her mom. So without slowing for even a second, Diamond kept pounding and pounding giving her the rutting of a lifetime.

What came out of her whore of a mom’s mouth shouldn’t have surprised her. “UHHN! DO IT INSIDE! FINISH INSIDE ME, DIAMOND! DON’T YOU DARE STOP!”

She didn’t. At the fastest speed the filly could muster, she bred her mother as pleasure consumed them both, and that feeling in her cock only got stronger as she did.

Whap! Whap! Whap! Whap! Whap!

Her climax only rose, and rose, and she kept striving to reach it, before-

“NGH! IT’S-!” With one last hefty thrust all the way back into her mom’s slutty cavern, Diamond didn’t stop pushing until her tip couldn’t go any further, and only when it was pressed against Spoiled’s womb did she unleash the tidal wave of cum she had ready to give her. “NGAAAAAHHHHH”

Hugging her mom’s ass to keep herself as deep in her as she could be, Diamond’s face showed the pure euphoria she felt as load after thick, white load blasted out of her balls and straight into her mom. It filled up her womb and then kept coming and filling her up some more. She wanted it to never end.

And on the receiving end of such a generous orgasm, Spoiled was going through her own. Currently cumming her brains out, she was feeling every last bit of her womb getting filled to the brim. It was almost familiar, she remembered a similar feeling years ago, when Filthy had gifted her a daughter, but now it was that daughter that was doing his job, and Spoiled Rich couldn’t get enough of it. “UNNGGGGHHHHHHHH!”

As the two remained attached, the bliss that both felt went on and on and on, even after Diamond stopped cumming. But not long after it was over, and plenty of cum had come gushing out of Spoiled and splattered down onto the bed, they were finished.

And the mother was a but more finished than her filly.

With everything coming to a halt, after Diamond Tiara slid her cum-covered cock out of her cum-filled, Spoiled dropped down onto the bed exhaustedly. She was tired after the best night of her life.

Meanwhile, with Diamond currently going through the sensation of feeling her cock soften, she stepped past her collapsed form to reach her head, and she stared down at it.

“So…” Panting with her mother, she spoke to her prone form. “You’re gonna leave me and the crusaders alone now, right?”

In a tired yet undeniably blissful voice, Spoiled responded back. “…Sure, Diamond. Do whatever you want. Just come visit my bedroom again tomorrow night.”

A wide smile took over Diamond’s face. She’d won! All her hard work had paid off, and now she was the one in control! Though admittedly, she hadn’t seen it going this way.

She went to agree, only for the downed mare to speak up again, cutting her off. “How about you sleep here with me tonight, Diamond? You can’t go to bed with your dick all messy like that, I’ll clean it.”

“Um… Okay!” And so, Diamond got a blowjob too in the same night that she’d lost her virginity, and went to sleep in her mother’s legs.

Meanwhile, outside the door, gaping through the crack in it, a stallion stood, an erect one that had gotten unintentionally cucked by his own daughter.

He’d only come up here to grab something for his job tomorrow, but ended up stumbling onto his own filly breeding her mother like a professional stud.

Needless to say, he watched.

But now, with the fun over, he had to go back downstairs to taken care of this thing himself…

At least he could come back tomorrow.

The next day, Diamond strolled through Sweet Apple Acres as a free mare!

Smiling brightly, she was no longer held on a leash by her mother. She no longer couldn’t see the Cutie Mark Crusaders. She was her own mare now, one that did what she wanted! She made the rules.

And so, with nothing stopping her, she made her way to the CMC’s clubhouse, cantering up to it before trotting up the ramp and letting herself in.

Inside were three fillies huddled around a book.

On her entering, Apple Bloom’s head turned to her, and she met her smile with a smile of her own as she called her over. “Hey! Diamond Tiara! Come over ‘ere! Check out all the funny positions these ponies are in in that book you brought!”

With a life of freedom ahead of her, and her two big balls bouncing behind her, Diamond did.

Author's Note

Alternate storyline:
All she had to do now was figure out a way to make it happen… somehow.
The next day, Diamond walks into a bar full of stallions. “Does anypony want to put their cock in my mom?”

Anyway, commission #3 down!