Big Sis, Better Witch - Pt. 1

TL;DR: This is a story about a sister and brother being pretty mean to each other in creative ways, and having a lot of sex.  There’s a ton of size change.  Major themes include unapologetic incest, blackmail, degradation, lactation / breastfeeding, and girls with penises.  If you’re not down for all that, change the channel.  Don’t @ me

This story is the product of one person writing all the taboo kinks that spoke to them in a particular moment, and putting them into one story.  As such, it's possible I'll be the only person who enjoys this story.  There's probably something in here for everyone to not like.  All the same, I hope you come on this journey with me.

Content Warnings: Brother-sister incest, dubious sexual consent, lactation, female cock growth, male cock shrinking, cuckolding, blackmail, threat of revenge porn, humiliation, non-consensual size change,  BDSM themes including: tickling, spanking, choking, hair pulling, and verbal degradation, arousal control, female growth, female shrinking, male shrinking, male growth, breast growth, male cock growth, muscle growth, muscle loss, mommy-dom themes, light fear play, sizes from 6 inches to 20ft, femdom, Underage alcohol consumption, Consensual pain during sex, Mommy Dom / Little play, crying, Dead Dove: Do Not Eat

Dead Dove, Do Not Eat?  If you don't know, Google it.  Basically, see those content tags up there?  All of them are in this story.  If you open this story, that's what you'll see.

Big Sis, Better Witch
by pseudoclever

My little sister’s growth spurt was getting out of hand.

It had started after her eighteenth birthday.  As recently as Christmas, Madison was laughably scrawny.  Our height charts in the kitchen tell the story.  She’d reached four-foot-four around her eleventh birthday, and then just… stopped.  As the two of us got older, I kept insisting that mom measure us every few months to see if maybe she hadn’t grown this time.  Even when we all knew damn well she hadn’t.

It was humiliating for her, I’m sure.  But it was fun for me to keep seeing my marks get higher and higher, while hers stayed the same.

That had been the story of her life.  Watching her older brother outgrow her.  Watching all her classmates hit puberty, start to develop, to out-class her in every way.  Well… almost every way.  Madison had an absolutely ridiculous pair of hooters.  They were G-cups the last time I snuck a look at her bra.  I’m not proud of it, but it was just sitting there in the dirty laundry.  I was curious, okay?

As long as I’m being honest here, I’ll go ahead and admit that I’ve never been particularly nice to her.  I teased her a lot – about her height, the size of her chest, whatever was handy.  If mom wasn’t around, things tended to get physical.  Nothing too bad – mostly just holding her down and tickling her until she gave up.  If you ever met her though, you’d agree she deserves it.  Because tiny or not, she’s always been a total brat.

Part of her bad behavior is just plain old sibling rivalry.  I’m a year older than her, and I totally lucked out in the genetic lottery.  Popular, good in school, good at sports.  I even managed to land a full-ride scholarship for college next fall.  Meanwhile, she was just this weird antisocial dwarf without a lot of friends.  She’s not good at hiding her jealousy, and what she lacks in stature, she more than makes up for in her ability to piss me off.

The worst thing though, is how mom always takes her side.  Telling me to be the bigger person, and count my blessings.  While the little shit is making faces at me from behind her back.  Even thinking about it right now is making me angry.

Anyway.  I was talking about her growth spurt.

It was just after spring break that I started noticing.  How Madison’s baggy hand-me-down shirts started to almost fit.  How she could reach things on the lower kitchen shelf without needing a step stool, or begging me for help.  From there, the changes got more obvious.  I swear I could see her getting bigger day by day.

Nobody in the house said anything about it.

Looking back, that was kind of weird.

I remember the first time it ever came up in conversation.  It was April, and I think she was around five feet tall.  We were sitting across from each other at the kitchen table eating breakfast.  Mom was hurrying to get to work.  She told us goodbye, and for the love of God please be good.  The door slammed behind her.

The very moment it did, Madison looked up from her cereal.

“I can see you staring at my chest,” she snarled.  “Stop it.”

I glared back.  “Don’t flatter yourself.  I wasn’t staring.  I was thinking about my date tonight actually.  If your dumb tits happened to be in my way, that’s your own fault.”

“I have eyes, Will.  You’re like three feet away.  I can see you looking down my shirt.  I’m your little sister, for God’s sake.  Exercise some self-control.”

“Okay, yeah.  We’re three feet apart.  And you’re wearing that low-cut top, without a bra.  And you’re so short, you’re resting your boobs on the table and like, pillowing them at me.  It’s entrapment.  How am I supposed to avoid looking at your fucking G-cups when you stick them right in my face?”

Madison pursed her lips, smirking at me.  “Hm.  They used to be G-cups.  But my boobs have grown a lot bigger since this growth spurt started.  How did you know what size they used to be, Will?”

I sneered at her, and didn’t say anything.

“You know how this is ending?” she asked.  “I think I’ll start a rumor about it at school.  How you were going through my underwear drawer, looking at my bras.  Everyone’s gonna think you’re a total pervo creep.”

Madison knew what came next.  She was already pushing back her chair, getting ready to run.  But we’ve played this game too many times, and I was ready for her tricks.

She tried to make it to her bedroom, to lock the door behind her.  She didn’t even make it to the stairs before I grabbed her around the waist.  Madison was already laughing, even before her punishment arrived.

I started tickling her.

“Stop!  Fucking… I’m going to tell mom!”

“That only means you’ll get it worse next time.”

She fought with me as I dragged her to the couch.  Kicking, and scratching, and laughing.  She had grown a lot, and she felt stronger in my arms too.  Like you could almost say she had biceps.  But I’m six-foot-two, and no slouch at the gym.  Even if she was kinda strong for her size, there really was no contest.

“Let me go you asshole!” she giggled.

I held her pinned beneath my armpit, face-down on the couch.  Running my fingers over all her most sensitive parts.  Her tummy, the back of her knees, the inside of her thighs.  I was really conscious of the weight of her breasts against my leg.  She was right – they had gotten bigger.

“Promise you won’t tell mom,” I snarled.

She held her breath.  But finally a giant sigh exploded from her lungs, and she started to cackle.

I pressed my advantage.  “You won’t tell anyone.  Say it.”

“I won’t!  I won’t!”

“Say you’re sorry!”

“I’m… ahhh!  Sorry!”

Usually I let her up as soon as she apologizes.  It’s only fair.  I’m not sure why, but this time I let it go on.  She screeched and struggled and swore at me.  And then she starting making this really weird noise – this soft, pathetic mewling from the back of her throat.

I sorta felt bad for her at that point.  Like she pissed me off, but I definitely hadn’t intended to take things this far.

I decided to give her a break.  I even wanted to let her feel like she won – because I really do try to be a nice guy.  I loosened my grip, and gave her a chance to escape.  

She didn’t take it, though.  Just buried her face in the couch, pressed herself into my hands, and let me keep tickling her.

I finally gave in and released her.  I was expecting her to stand up right away and run off.  But she didn’t.  She just lay across my lap, breathing hard, and shaking.

Her face was red and puffy when she finally stood up.  She wiped her eyes, and looked down at me with this pathetic expression.  I thought about apologizing.  I didn’t.

“You were, though,” she said, in a tiny voice.  “Staring at my tits.”

“Are you trying for round two here Madison?”

She shook her head, hard enough to make her bangs smack her in the face.

“Go wash up.  You’re a mess.”

Madison nodded.   She took two steps.  And then turned back to look at me.

“If my growth spurt keeps up, you won’t be able to do that to me anymore.  I’ll be too big for you.”

She said the words without emphasis.  Not a threat, or a prediction.  Just words.

“Even if we were the same size, I’d still be strong enough to turn you over my knee and make you cry for mercy.  And no way is any growth spurt on Earth getting you up to six-two.  You’ll always be less than me, Madison.”

She opened her mouth to say something.  But then she shut it, gave me a bratty-little-sister smile, and ran off to get ready for school.

I didn’t see Madison at all after we got home that night.  Which was weird.  Usually when my girlfriend is coming over, Madison finds a way to be underfoot.

Tiffany and I were in my bedroom.  We were watching a movie on my laptop.  Ostensibly.  Actually, we were making out.  We’d been together for about a month, and so far, making out was all we’d done.  I really wanted to take things further tonight, and I had the feeling she did too.  In my humble opinion, Tiffany was the hottest girl in school.  Long blonde hair, perfect softball sized breasts.  And she had this really adorable way of half-moaning, half-laughing whenever I stuck my tongue in her ear.

It was only thirty minutes until her curfew, and things were starting to get hot and heavy.  She was breathing hard on my neck, and I had my hand under her shirt.  My fingers were massaging up her back.

“You can do whatever you want with me,” she whispered.

My hands shook with eagerness.  I started to unhook her bra.

“But shut the door first.”

I froze.

“What’s wrong?” Tiffany asked.

“Nothing.  Give me a second.”

I stood up, tucking my erection into my jeans so it wasn’t too obvious.  I was completely sure I’d already shut that door, and I had a sneaking suspicion I knew who opened it.  In three quick steps I was out in the hall.  I half expected to find Madison – on her knees, caught in the act of watching us.  But she was nowhere to be found.

I tip-toed down the hall to her bedroom.  I peeked around the door… and saw her playing some computer game, listening to her headphones.  Her back was turned, and she was acting like she didn’t know I was there.  She almost had me fooled, she really did.  Except I could see the little pink blush on her neck – a dead-giveaway that she’s trying to get away with something – and she was also sweating a little.

Plus her headphones weren’t plugged in.

Tiffany was still sitting on my bed.  “Let me guess.  Madison was spying on us.”

“Beauty and brains.  You really are the whole package.”  I kissed her.

She returned it, but it was more a casual kiss, nowhere near as intense as before.  Apparently the mood was gone.  “It’s the third time she’s tried to watch us make out.”

I cracked my knuckles.  “Don’t worry.  I’ll set her straight.”

“Make sure you tell me how that goes.  In detail.  But honestly, I feel kind of sorry for her.”

“Seriously?  You’re not creeped out?”

“Hmm?  A little.  I guess.  But she’s no threat.  She's one of the least popular girls in school.  She always sits off to the side at lunch, and she never talks to anyone.  I know a couple people who are curious about her – what with all the growing she’s been doing, and her, you know….”

“Huge boobs?”

“Those, yeah.  But something about her puts people off.  Or maybe like, she’s trying to keep them away.”

I’d seen Madison’s little sulking act first hand.  We’d shared second and fourth periods last spring, and I don’t think I ever saw her talk to anyone but the teachers.  I could probably have tried to get her to open up, introduce her to a few people.  It seemed like too much of a hassle.

“So I get it,” Tiffany was saying.  “Why she’d be curious.”

I scoffed.  “About her brother’s sex life?”

“About her hot brother’s sex life,” she corrected.  “Assuming he actually has one.”

I grinned, and gently pushed her back down on the bed.  “Well that’s up to you, isn’t it?”

When I reached for her chest, she rolled toward me.  Pressing her breast into my palm, arching her back.  She moaned, almost theatrically loud.

I looked over my shoulder, making sure the door was still closed.  “What, do you actually want my sister to overhear?”

Tiffany pursed her lips, and seemed to consider the question for a long time.  “I don’t know.  The idea is kind of… sexy.  Don’t you think?”

“Okay, but if you get any louder my mom will hear us from downstairs.”

“Now that’s definitely sexy.”

I laughed.  Sure now that she was kidding.  Tiffany has a great sense of humor.

I almost succeeded in undressing her, because this time she was helping me.  But then we heard my mom’s footsteps on the stairs, and had to get back to just watching the movie, fast.  Mom knocked, and told me it was time for the two of us to say goodnight.

At the front door, I kissed Tiffany again.

“Hey,” she said, softly.  “Just so your sister really has something to be jealous about.”

She lifted her shirt, flipped up the cups of her bra.  And flashed me.

I made it back upstairs, still feeling dazed.  Madison was lying on her bed, typing on her phone.  Resolutely ignoring me.  I thought about confronting her, telling her I knew she’d been spying.  But I knew she’d deny it, and we’d just get in a stupid fight.  I’d end up tickling her, and mom would have to break it up.

So I got in my own bed, and thought about happier things.  The sheets still smelled like Tiffany.