Step-Siblings' Shared Wall

Sadie had always shared a wall with her step-brother Sam.

Her father had died when she was just a baby, and her mother had soon re-married, making John the step-dad that had always seemed like a dad, and Sam the step-brother who had always seemed like a brother. They lived together and had grown up together, and Sadie had even taken John's surname. To a casual observer, they seemed like an ordinary family living a standard life in a normal house in a regular town. In fact, to any outside observer, nothing would have seemed amiss. This is because the thing that made their family not ordinary was on the inside - specifically, on the inside of Sadie.

Sadie had a secret which she kept locked up tight in the most secure location in her mind. It was the kind of secret that she knew she could never share with anyone, even (especially!) with her own family. But it was also the kind of secret that burned brighter the longer she kept it secret, and ever since she and Sam had turned 18, Sadie had felt this brightness burning harder than ever.

The wall that separated their bedrooms was thin drywall. Sadie knew exactly how thin it was, because their beds abutted it on each side, and Sadie had always been able to hear a good deal of happenings on the other side. Sadie was slightly older than Sam and, in her mind, a lot wiser, so she felt she had been first to realize the importance of keeping certain things quiet in bed. She felt that Sam was the complete opposite, taking no care whatsoever. At first she was disgusted and annoyed at being kept awake, and wanted to storm into Sam's room, catch him in the act, and tell him off, but she couldn't muster the confidence and didn't really want to see him do it anyway.

Over time, Sadie grew to tolerate, and then even to enjoy the nightly rhythmic squeaking noises of Sam's bed next door. It gave her a sense of power over him, like she knew his secret, and could reveal it any time she wanted. She came to learn his patterns. He would usually do it late at night when he thought everybody else had fallen asleep - another reason for Sadie to keep still and quiet in her own bed. Sometimes Sadie would lie half-asleep, not knowing if perhaps the noises were in her dream. They would usually start as a quiet squeak of mattress springs, proceed rhythmically, and then intensify - sometimes to the point where the bed began knocking slightly against the wall. It was usually at this point that the speed of the rhythm increased - faster and faster, with urgency... until it suddenly stopped, and silence descended for a minute, and then she would hear Sam getting out of bed to go to the bathroom.

At some point along the way, Sadie had begun touching herself at the same time. Part of her was just being practical - the safest time to do it was when there was already noise. She kept her movements to a minimum, usually lying face down and squeezing her fingers between her legs. She hoped that whatever incidental noises she made would be lost in the noise that Sam was making. Occasionally she would mis-time her self-pleasuring, and Sam would finish first. She felt unable to continue at that point, worried that there was nothing going on next door to mask the sounds of her carrying on. A long, frustrating, touchless night would follow.

Eventually Sadie trained herself well enough to hear Sam's pattern starting, get into position, and finish at the same time as Sam. She even slowed down if she felt she was getting ahead of Sam. She wanted to achieve climax at the exact same moment. Her orgasms became tied to Sam's. She would visualize what was happening, inches away from her through the wall. Was he doing it under his sheets, or in the open? What would she see if she drilled a little hole through? Did he use a sock, or what?

This was Sadie's secret: her sex life had become interwoven with her step-brother Sam's. He knew nothing about it at all, and she could never tell him. Besides the embarrassment, she didn't want to risk their tacit arrangement coming to an end.

Everything changed the night Sam brought his girlfriend home for the first time. They had met at his 18th birthday party, and were planning to go away to the same college. Sadie was already feeling mixed emotions - on the one hand, proud of Sam for getting into a good school; on the other, sadness that they would no longer share their wall. Sadie was going to a different college. The thought of solid block walls in a strange dorm filled her with trepidation.

Sam had been dating Gracie for a while; they were a perfect match: Gracie's tall, athletic figure, and Sam's equally buff physique (Sadie had noticed). Sadie knew it was only a matter of time before they took things to the next level in their relationship. Sam had been spending a lot of time over at Gracie's; for all Sadie knew, they could have taken it to the next level already.

All doubt was removed the night Gracie came over for a movie & popcorn evening. Sadie's mom and step-dad were away, so they had stayed up late with the house to themselves. When the movie finished, rather than Sam offering to drive her home as usual, Gracie had announced that she was tired and that they were heading off to bed.

Wait, Sam's bed?! Sadie thought to herself, almost panicked.

She was taken by surprise at the obviousness of it.

"OK guys, see you in the morning I guess!" said Sadie, trying to work out her next move. All she knew was that she had to be up in her own bed as soon as possible - she didn't want to miss anything. "I'll probably head off myself soon, it's been a long day".

Sam and Gracie shuffled each other out of the room, not trying to hide their handsiness with each other.

Sadie sat on the sofa staring at the muted TV. She waited 60 seconds, then bolted up the stairs as fast as she could without making a noise, then slipped into her own room and locked the door. She turned off the light, crawled into her bed, and began to listen.

She could hear Gracie giggling. She could hear them move about the room. Gracie seemed a little more switched on to the situation than Sam; Sadie was sure she'd heard her give out a "sssh!".

It wasn't long before Sadie heard the sound of bedsprings. She strained to listen for words, but they must have been whispering and trying to keep quiet.

"You don't have to, Gracie," said Sam, audibly through the wall. This elicited another "ssssh" from Gracie, and then there were no more words, just the rustling of bedsheets and the irregular squeak of springs.

What were they doing? thought Sadie. This was not a pattern she recognized. There was clearly movement of some sort, but it was... gentler? Less rhythmic, less insistent, perhaps smoother?

Suddenly Sadie heard Sam let out a low moan. What was she doing to him?

The new noises continued, and Sadie's mind raced as she tried to fit them to what she knew of sexual positions and activity.

Sam moaned again - and then something else. Perhaps a kind of sigh, or sharp exhalation of breath? To Sadie's comfort, a bedspring rhythm was developing, with familiar building insistency. She slipped a hand under the elastic of her panties, sure she now knew what was happening. Oh Gracie, you slut! she thought as she rubbed herself. Sadie began her usual trick of timing her own rhythm to the sounds she could hear - but it was different this time. Something new. A new feeling came over her... was this... jealousy? Or envy.

Suddenly the rhythmic noise stopped, and she heard the muffled, ruffling sound of someone readjusting their position.

"No, please! Don't stop!" she heard Sam say.

"Sssh, keep it down, you clutz," she heard Gracie hiss, and then something whispered and inaudible.

Sadie wondered if Gracie suspected anything. Did she think Sadie was still downstairs, or had she heard her come up to her room? What did she suspect about the thinness of the wall?

More shuffling, and then the return of the rhythmic movements, re-building to their previous pace. Sadie frigged herself furiously now, driven by her imagination of what was happening on the other side of the wall. Was her imagination running away with itself, or did she hear... a wet smacking noise?

It sounded very much like Gracie knew what she was doing. The rhythm was like a metronome - focused, determined, consistent.

Suddenly, she heard Sam let out a muffled groan, and Gracie let out an equally muffled squeal of delight. It sounded like Sam was trying his hardest to stay quiet, perhaps holding a pillow over his head as he grunted uncontrollably.

Soon the noises died down and were replaced by more shuffling.

"Fuuuck," was all she heard from Sam.

Sadie imagined them snuggling up to each other. She thought she heard whispers, but the wall was sturdy enough to prevent them coming through clearly.

In the novelty of the action, Sadie had mis-timed her own act, and she was left throbbing and unsated. Gentle silent swirls on her nub weren't enough. She felt she was blocked, and wished they would get back to action next door - but it didn't happen. Sadie presumed they had fallen asleep. Reluctantly, she did the same.

The next morning, Sadie awoke and sat bolt upright. In her dream, she had been in Sam's room, watching Gracie go to town on him. She had felt a burning envy at this stranger who had come in and taken Sam away from her and done things for Sam that Sadie never could.

Sadie shook her head and took a swig of water from her bedside table. She pushed those thoughts all the way down.

She changed and left her room to go down and make some breakfast, but found the house empty, and Sam's car gone. They must have headed back to Gracie's early, she thought.

Sadie set about making some Saturday morning waffles, thinking to herself. Her loins still burned, unsatisfied. She decided to head back upstairs and finish herself off in peace, now that the other two were gone.

As she headed to her room, she noticed Sam's door wide open. Normally he was fiercely protective of his privacy and kept it both shut and locked. Sadie decided to indulge herself and take advantage of the situation.

She crept into Sam's room. There was a certain smell that she didn't quite recognize. The bed was unmade, there were clothes on the floor and over the chair, and his laptop had been left on. Typical boy, she thought. Sadie looked at the rarely-seen other side of her shared wall and admired it like a it was an old friend.

On the bedside table was a box of tissues, and a bunch of tissues in the nearby wastebasket. An awful, terrible, naughty thought crossed her mind. She reached into the basket, gingerly removed one of the scrunched-up tissues, and gave it a sniff. There was something about it... something familiar. It was still slightly sticky - a clear colorless stickiness. She picked up another of the used tissues. This one she couldn't identify. Something that smelled a little like... bleach, perhaps? Her mind raced. Had Gracie wiped herself? Had she spat? Sadie felt an illicit thrill run through her veins. To her own surprise, she felt compelled to bring the second tissue closer, for a deeper sniff. She ran the wetness across her lips, then licked. Salty, she mused.

Just then, Sam's car came up the driveway.

Damn thought Sadie, tossing the tissues back in the bin and tiptoeing out of the room. She hurried back downstairs and resumed making breakfast just as Sam came in through the door.

"What's cookin' sis?" he shouted.

"I'm making your favorite - vanilla waffles!" she shouted back.

Sadie gave her lips an extra lick, paranoid that anything might still be on them.

Sam came into the room.

"You're so awesome!" said Sam, coming over to give her a rough-and-tumble hug. Sadie's heart skipped a beat, and she awkwardly hugged back, worried that her little trip into Sam's room might have left some kind of evidence on her, somehow.

"I am, aren't I?" replied Sadie with a smile. "You're gonna miss this off at college. Sure you don't want to change your mind?"

"Are you kidding Sade?" said Sam, "This is everything I've always wanted - I mean, don't get me wrong, I love your waffles, but come on, I've got to take that next step. Besides, Gracie's going, and I can't be without her. She's awesome too y'know?"

I bet she is thought Sadie, with a little bitterness.

"Yeah, I guess," she responded diplomatically. "You seemed to be getting on great last night at least."

Sam didn't answer for a moment.

Shit, did I just give something away? thought Sadie.

"Uh, sure, I mean, we're going steady now," he responded.

I wonder how long that's been going on for, she thought.

Sadie served breakfast and they ate together at the kitchen table while catching up on their messages.

"You know there's a scholarship on offer that I think I could ace?" said Sam. "I'm going to go write up my application OK?"

Sadie gave a disinterested uh-huh and let him go. She had a part-time job later that afternoon and was about to head off herself. She worried that she had divulged part of her secret. Was Sam going to be more cautious now if he thought he was being monitored? Oh god, was Sam even going to carry on his regular sessions at all if he had Gracie to do it for him now? Sadie wore a concerned look.

She finished up and left the house, still carrying the buzz of interrupted un-satisfaction that she could no longer do anything about.

That evening, Sadie got home to find Sam still at work in his room. She was tired and wasn't hungry.

"Sam, I'm not eating anything tonight. You can go microwave a hotdog or whatever if you like," she called to him through his door.

She heard Sam get up and rustle for a bit, then came over to open his door and poke his head out.

"You sure? You not feeling well or something?" he asked.

"No, I'm fine, it's just... it's been a long day and I had a late lunch with the office girls," she said.

"Sure, OK. I'll go down and sort myself out," he responded. "Just give me a second OK?"

Despite her own fuzzy head, she thought something seemed off about Sam. Was it just her imagination, or were his cheeks flushed?

She went into her room, closed the door, and flopped onto her bed.

This bitch Gracie... she thought to herself, protectively, but aimlessly.

She soon heard Sam head out of his room and go downstairs, presumably to make himself dinner. This is my chance, finally, she thought to herself. She rolled into her usual prone position and pushed both hands down into her panties.

What did you do with my step-bro, Gracie? she thought to herself, angrily, as she rubbed herself hard.

Why are you seducing him like this? she continued, slipping a finger inside.

I swear, if you are taking advantage of him in any way, Gracie... she imagined, as she pressed into her clit firmly.

He's not that kind of boy Gracie, you slut! thought Sadie, feeling anger and resentment and horniness well up inside her in unison.

He's powerless to resist, Gracie, you must know that! What did you do to him last night, Gracie? Did you suck him? she thought to herself, wildly rubbing her sopping pussy.

Is that what you did, Gracie? Did you have his cock in your mouth, you whore?! she said to herself, desperately, rocking her hips in time with her hands now, feeling her wetness seep through her fingers and into her panties.

And did you try to keep him quiet, so I couldn't hear? Did you know I was listening Gracie? Did you?! You tried to keep my own fucking brother quiet while you sucked his fucking dick, Gracie? You only took your mouth off him for long enough to shush him and keep me from hearing him? Is that who you are Gracie? A cock-sucking bitch, shutting me out! It's my fucking house, my fucking wall, Gracie! And he's my fucking brother, Gracie! You hear that? He's mine! she ranted deliriously to herself as her engorged clit slipped between her fingers and she squeezed her legs together.

Sadie was rocking herself mindlessly up and down, lost in a fantasy of vengeance and arousal.

"Fuck!" she cried audibly as she came, finally releasing more than a day's worth of pent-up frustration, and shuddering into her mattress, waves of pleasure emanating from her clitoris as she crushed it beneath her fingers.

She gave out a deep breath into her pillow.

I needed that, she thought to herself.

"Sadie, are you OK?" Sam called through the wall.

Ohmygod... she thought. How long has he been back in his room?

"Yeah, I just, uh, stubbed my toe," she lied. That was the best she could come up with.

"You need a band aid?" he called back.

"No, no... I'm fine. It's fine," she replied.

She sat on her bed replaying the last few moments. How much had he heard? She hadn't been taking care to stay quiet at all. She had been lost in this stupid hatred of Gracie. Why did she hate Gracie anyway? Sadie felt ashamed.

She got up and changed into some fresh panties, then wiped her fingers down and tried to freshen herself up for bed. She sat at her dresser, brushing her hair, looking at herself in the mirror, wondering who this person was that had been thinking those awful things over on the bed.

It's really none of my business, she thought, guiltily. He's an adult now, he can see who he likes, he can sleep with who he likes... he can get... sucked off by who he likes...

Her thought trailed off as she once again got caught up in the vision of Gracie going down on Sam. She licked her lips and recalled the taste from the tissue. In her imaginings, she saw Gracie bobbing up and down on Sam's hard dick, like a succubus. The scene was vivid in her mind, and she began to feel her nipples re-harden. The Gracie in her vision was suckling at the tip of Sam's erection now, tasting his pre-cum. And now it was Sadie herself, tasting it on her lips as she took his length into her own mouth...

No! she cut herself off, standing upright. No, it's wrong.

She put the hairbrush down, but as she did so, she was surprised by a noise coming through the wall. A familiar noise... a familiar rhythm...

He's doing it right now! she realized.

It was earlier than usual, but nobody else was in the house, so Sadie thought he must have just had a long day working on his statement and needed a bit of release. Her imagination ran wild, fuelled by the vision she had had of Gracie... and of herself.

She crept back into bed, and began once again to touch herself, following her usual pattern. Sam was getting into the swing of things, by the sounds of it. She increased her pace, buoyed by her own recent orgasm. She felt good. She was back in the pattern. Sam touching himself, and Sadie touching herself - together again.

Sam let out an audible deep sigh.

This wasn't the pattern.

Sam never usually made sounds on his own. And now, just moments after speaking to her through the wall? Surely he would now be perfectly aware that Sadie was right there, and perfectly aware of what level of sound was audible? How much had he heard earlier? Sadie rubbed faster at the thought, and something caused her to loosen up her caution a little. This was off-pattern too. She caressed her slickening vagina according to the pace it demanded, without regard for her own bedsprings. She suddenly found herself face to face with a new exhibitionist streak in herself. Every time her thoughts turned to the noises she was making, and the possibility of Sam hearing, her crotch throbbed.

"Unnnghh," she exhaled, and a moment later Sam replied with his own short grunt.

Was he now... aware? she thought, not stopping her fingers. The idea gave her a surge of arousal and she felt her orgasm approaching.