Chemistry (closed)

He cursed, running his hands through his long blond hair, cursing as the ingredients in the vial fizzled, no color change or apparent precipitation as expected

This just wasn't working, he thought to himself. Then a sudden banging at the door caused him to jump, which of course led to the vials he had worked with to fall over.

"Damnit! What is it" he called out. Stomping up the basement stairs to the locked door at the top

"WhAt!" He practically barked as he opened the door

His sister stood there with earbuds in chewing gum loudly. He could have strangled her. He reached up and yanked on her headphone cords.

"Yes sis" he said brusquely, his temper ebbing. The blond beauty had always had that effect on him

"Hi!" Kelly chirped. She had her long blond hair up in two high ponytails. Even with her hair pulled up her hair came to her mid back. She was wearing a sports bra and tight yoga pants. She just finished a run and she was a little sweaty and feeling more tired than normal (she had been out the night before).

"I was wondering if you could whip me up some of that energy supplement thing you had me try a few weeks ago. I'm feeling a little drained and I haven't even finished today's exercises." Kelly was on the school gymnastics team and she needed to stay in shape and do lots of stretches... And when she did she always made sure to have an excuse to bother her brother.

She blew a bubble with her gum as she waited for his response. She was pretty sure that he wouldn't say no. After all, she was his personal Guinea pig when he needed one.

He was about to slam the door in her face, well honestly she could probably put up one hand and stop the door dead. His eyes quickly slid over her curvaceous athletic form. The sports bra containing a chest that was excessively large, and the yoga pants clung tightly.

"Sure. Come on down stairs" he said as he turned and led her down, his tall skinny gram cast a bit of a shadow, but that was countered by his pale complexion. He was almost her opposite in every way it seemed

He glanced at the desk with the spilled vial, he had a drain with a catch on it for any caustic chemicals, and decided to just go with that. He new the drugs he had been playing with when things spilled. And they weren't toxic, it was her fucking fault after all too

He grabbed the little bucket on the side of te tble where it had drained. He grabbed a beaker. Then poured some in

"Here you go" he told her as he offered her the glass, his grin a little large, he better it tasted awful.

"Bottoms up on this one. You gotta drink it all for the full effect" he told her as the pert bouncy blond accepted the drink.

"Thanks, big bro," Kelly smiled happily. She was completely in the dark about ruining her brothers experiment and the concoction was actually his way of getting back at her.

She took the beaker drank it down quickly. It had a surprising taste, much different from the last one she drank. She licked her lips. "That's actually not bad! Thanks." She pushed up on her toes to kiss his cheek. Her breasts brushed against his chest from the close contact. Kelly was always affectionate with her brother even if he found it annoying at times.

The bucksom blonde turned and started to go up the stairs until she was hit with a dizzy spell. Everything was spinning and she gripped onto the railing as her legs gave out from beneath her. "Bro... I feel..." And then everything went black.

Her hand released the railing and she came tumbling down the stairs until she was sprawled out on the bottom of the stairs.

Her kiss was too much. It was that effect she had in him that made him so mad. She had to know she was gorgeous, and a knock out to boot. And she was very very aware of his lack of social life.

He felt her breasts slide against his chest. Driving him mad. He could aware she did it on purpose, but he knew that she was a complete ditz about somethings too.

She turned to leave and he was just about to get back to work when he heard her mutter

He reacted just fast enough to catch her, but he was the opposite of athletic, and the two fell to the floor in a heap.

"Jesus sis" he said in a half curse, finding himself under her, turning his head he could see her eyes closed. She had passed out! Then he realized that in his attempts to catch her, his hands were gripping her hefty tits. His eyes slid back over to hers, ten down to his hands. He gave her chest another squeeze.

Oh god. The first time he gets to feel boobs and they are his sisters! Life just isn't fair.

He slid out from under her, checking her pulse and breathing. Then he looked around, and saw a glass of water. He got up and splashed that on her, suddenly waking her.

Kelly was doused with water and actually stayed laying there for a few moments. The drug that her brother assumed was ruined had actually overloaded her senses which caused her to passout and was rewiring her brain. When the fog in her mind finally started to clear she eyes opened. The world was still spinning but it was finally starting to settle. She felt... Weird. There was something different but she had no idea what.

"Ugh, what happened?" She asked. Her brother said something and she turned her head towards him.

Her eyes went wide when she looked at him. It was like she was seeing her brother for the first time, but not in the way a sister should normally look at her brother. Her heart started pounding. She was taking all of him in and she started wondering how she never noticed how perfect her older brother was.

He was saying something! What did he say?! How could she be so selfish and not be listening to what her brother was saying?! "What?" She asked. Still sitting there on the ground, dripping wet from the water he spilled on her. Kelly didn't realize that she was actually in a pretty provocative pose as she was gazing at her brother.

She sputtered, coming up off the floor. She propped herself up, her chest thrust forward. Her legs had lifted slightly too, and they were spread wide before him. He looked down watching her as she gathered herself

None of those drugs should have had that effect, he thought to himself as he watched her pull herself together. She seems a little fuzzy at first, almost like she was lost.

"Are you ok?" He asked, getting her attention as Sam stood over her

This wasn't good. That should not have happened

"Come on sis. You fell down the stairs. Let's get you up to your room so you can lay down. " he told her, reaching down to help her up.

He quickly led her upstairs, well up the stairs he followed her, putting his hands on her hips, her ass directly in front of his face.

God she had a killer body!!

Once up the stairs he hooked an arm around her waist and led her to her room. He helped her onto the bed

"You need to get out of those tight clothes so your body can relax, let me get
You some water too"he told her as he helped her to sit down on the bed. Then he went to the bathroom and grabbed a glass of water, walking back into her room. He froze at the door, his eyes stuck at what he saw her doing

Kelly was in heaven the whole time her older brother helped her up and to her room. She was so lucky to have someone so caring to look after her while their parents were away, not that she needed a babysitter.

As he put her into bed she heard him say that she needed to get out of her clothes which triggered her to start pulling off her sports bra as soon as his back was turned. Her breasts felt fantastic to finally be free from that garment, it was painfully obviously that it had gotten too small. Her nipples were a light pink and hardening from the feel of the cool air. Then she wiggled out of her yoga pants. She didn't have any underwear on so when Sam came back into the room she was sitting on her bed naked like it was the most normal thing in the world. Kelly also shaved, and she was making no attempts to cover herself up.

"Thanks," she said, acting aloof. "I must have over did it when I went running." It was the only logical explanation she had for passing out.

Kelly was sitting there, happily waiting for him to come into her room but he seemed to be frozen. She started to get worried. "Hey, are you ok?" He looked surprised. Did she say or do something weird? She recounted her actions. He told her to get out of her wet clothes. She did that. Then she thanked him for taking care of her and said that she probably ran too much. What was it that had him so stunned?

He felt his cock throb, and begin to swell as he looked at her sister. Her breasts hung full and round, her light nipples growing darker as she watched him. Each breath made them swell ever so slightly, god they were even prettier than he had imagined.

Then his eyes trailed lower. Over her toned sexy tummy to the shod owed space between her thighs.

He shook his head, wondering if she had hit her head, normally she would have screamed at him to get out. She seems to like to torment him, but that was lol through clothes methods. Tight clothes, skimpy clothes, thin clothes. But there hand always been clothes

He stepped closer, trying to fight his growing erection

"You didn't hit your head did you?" He asked a she got close enough to offer her the glass

"Do you have a fever?" He asked trying to determine what was going on. Then he recalled that the last vial had had what some termed a decorum reducer.

The drug simply made things ok. Kinda like lowering inhibitions but a little different.

Was. That what this was, he decided to try something

"Hey sis. Can you stand up and turn around for me?" He asked her. Ready with an excuse about checking her temperature if she protested.

"I feel much better now," she smiled at him. When he asked if she hit her head or had a fever she shook her head. "Nope! I feel ok. It's probably what I said before, I just over did it when I went running.

Then he asked her to stand and turn around. Without question Kelly got up, fully displaying all of her glory to him before she turned around and he got a view of her perfect round ass.

He smiled

This was insane!!

She had popped up, her full chest jiggling delightfully, then turned about, letting him eye her ass, openly, hungrily. He felt his cock throbbing, growing stiff inside his shorts as he eyes her.

"Hey sis. You mind if just check you over?" He asked as he stepped closer

"Go ahead and bend over. Put your elbows on the bed,, and arch your back. Need to see if there are any problems with your movement after that fall"

He wasn't sure the excuse mattered, but he felt better saying it as he stepped closer, reaching a hand out to her waist.

Kelly looked over her shoulder and shot him a look that said 'I don't believe you.' She might have been more susceptible (more like compelled) to his requests but she wasn't stupid. She was a gymnast, she had been examined before when she had bad tumbles. Still she did exactly as he asked and bent over.

She felt his hand touch her waist she was was very aware of the position they were in. Her heart was pounding. She didn't care if Sam made an excuse, she would let him touch her whenever and wherever he wanted! She loved the feeling of his hands on her bare skin. He didn't even touch her anywhere else and there she was getting excited.

No part of her thought anything that her brother was doing or about to do was wrong. It was like it was perfectly normal. She wondered where else he would touch her.

He let his eyes crawl over her, his other hand sliding up to her waist, on the other side, and he imagined what it would be like to take her from behind. To grip her hips like this and drive into her

He shook his head, letting his hands slide free from her waist and he slowly moved to her side, his one hand trailing up over her back, her compliance was amazing, and he cold my help but wonder how far it could go? Would she remember? Would she be mad?

Strangely the morality of it never came into question. He didn't care that he was listing over his sister so badly, that his trapped cock was painfully close to tearing free from his jeans

His hand slid down, cupping the full round curve of one ass cheek, and he gave it a squeeze, muffling his own groan as the balance between firm ass and plump rump yielded to his squeeze

His eyes slid down from her ass and over her waist, eyeing the hanging swell of her tits. They were full and heavy, yet some how pert and firm.

He let his hand slide down over her waist, and up toward her chest. Feeling the hefty weight of one tit fill his hand

His cock practically burst free at the sensation. His first real tit. And it was amazing!!

He swallowed hard. Worried about his next move. But she was sooo, impressionable. And he wondered what she was thinking right now and then it hit him.

"I want you to show me what you think I'd like right now". The demand was open ended. And it relies entirely on her interpretation of the situation

"I want you to show me what you think I'd like right now"

The wording he used was show not do. So Kelly turned around and sat on her bed reached to the floor and pulled up her laptop. Quickly she opened it and opens her web browser. Under normal circumstances she would have been careful not to let him see the windows that where currently open.

Sure there was the normal online dress shops, schools she was applying too... But there was also a few adult stores she had been looking at too. Opening a new page she did a quick search and found a few videos. She played them for him. One was of a girl giving a guy head, another was a couple fucking, and the last video was of a guy cuming on a girls chest.

"You know, grabbing my tits and ass while sporting a hardon is a bit of a dead give away," she smirked at him. The drug certainly didn't take away her teasing nature.

He wants to her as she turned around. On the way she moved and the way her soft around flash shifted. He was surprised when she pulled out her computer but watched every move she made as she pulled up videos of exactly what he wanted to see and what he wanted to do but he couldn't

He hath chuckled and turned red from her statement about how obvious he had been But she was right he wonder it was true he wanted to do those things to her never done those things to anyone who wanted to know what it was like you needed to know and there was no deny how beautiful his sister was

" do you want to see my cock ?" He asked in the thick heavy voice as his eyes went from the screen with a chesty blonde come over her chest and back over to his sister so firm skin but it was real and it was there in front of him and she seem to be willing to do just about anything

Did he dare take it this far what if she remembered what if she was mad what offense the drug war off she told her parents

But he wasn't thinking like that he was thinking with his dick in his dick was tired of being stuck in the shorts

" go on and take it out if you want to see it" he said stepping little closer to her waist just below I level where she sat on the bed

Kelly couldn't help but she smile when she saw her brother blushing. She didn't have a whole lot of experience but she had a sneaking suspicion that she had more than Sam. She didn't even think he ever had a girlfriend.

Then he asked her if she wanted to see his cock. Normally this would be where she would blush and act offended and yell at him to leave... But now she was fully naked and the two of them were looking at porn off the internet. I think they were past feigning modesty.

Then he told her to take his cock out if she wanted to see it. Without thinking she pushed the laptop aside and moved closer as her hands quickly opened his pants and started pushing his jeans down until she could reach in and find his cock.

"Holy shit, Sam!" Kelly exclaimed when her fingers tried to wrap around his girth and found that there was a gap between her fingers and thumb. Pulling it fully out she found that his length matched his thickness. Kelly had only been with one guy and he was average. Who fucking knew that her brother was hiding a monster in his pants?!

Instead of letting go and letting his cock stand tall and proud, Kelly couldn't help but to start stroking his shaft. God... If he wasn't her brother...

For some reason that thought didn't deter her. She was already stroking him, would it be so bad if she entertained the idea of fucking him. Her hand gently slid up and down his length. He was thick and smooth and everything a girl could hope to find when they first sleep with a guy.

He was frozen, she had moved so quickly and almost nonchalantly. Of course there was nothing about any of this that made sense, and he should stop being surprised. After all he was a smart kid and had apparently created a cocktail that increased a persons willingness to comply and removed inhibitions.


That still didn't change the fact that his sister, a girl of remarkable beauty and physical perfection, was naked and complying to every request he made. It was
Unreal

And unreal is how he would describe what happened next.

The beautiful naked blond, very smoothly, pushed the laptop over, slid closer to the edge of the bed, and with fingers that worked quicker than he could imagine, had his pants Undone.

Her eyes were fixed on the swollen tent of his trapped cock before very deftly tugging him free

Her reaction was what he had hoped. He was no moron, he knew he was endowed, and honestly he had expected that fact to somehow get him so many girls, but he had never had the opportunity to share his blessing

She was the first one to see or touch his cock. And touch she did

Her had began to slide up and down his swollen shaft. She was very interested in what was in her hands, her eyes sliding over his girth and length, a new look in her eye that he had never seen before.

The way she felt was....it was so far beyond masturbating, he couldn't even describe it. His blood was boiling, his heart racing, his skin on fire!!

"Oh god!!" He growled, then his cock throbbed, one heavy twitch, and hours of cum spewed from his member. The brief attention his sister had so casually given it was more than he could take

Thick gooey streamers of cum spattered all over his sister as his head exploded with extasy.

Kelly was surprised with not only how quickly but also by how much her brother came! It was a good thing she moved the laptop. It was also a first for her, Kelly had never been cummed on at least not like this, not completely covered. There was a stream that went across her face, some even got on her lips. Then it was all over her chest, not to meantion her hand.

"Do you always cum this much?" She shifted a little on the edge of her seat, trying to imagine what it would feel like to have this much cum shot inside of her. Oh god, she could imagine how it would feel pulsing inside of her!

Kelly was smiling to see that she made her brother cum. She helped to make him feel good and there was a strong need to please him. Grabbing the towel she had in her room from her shower earlier today she gently wiped clean his cock before. Wiping off his cum from her body. She needed another shower after her run anyway.

"Alright boy genius, I need to shower now." She playfully kicked him out of her room.

She didn't freak out. She didn't scream. In fact she seemed like she liked it. She liked all his cum on her

It had been a lot, his body seeming to just keep pumping cum onto her. It was insanely hot!

He almost wanted to counter her question with a compliment of how good she looked in it

She say there, his sticky seed spattered, and slowly rolling over the prodigious swell of her tits, a thick gob on her chin and across a lip.

But she just casually grabbed her towel and wiped him and her off.

His body had twitched and spasmed as she sleazed him up

"I do actually" he said in a delayed response to her question. But at that point she was corralling him out of her room. Before he knew it he was standing in the hallway with his cock hanging from his open pants, slowly deflating.

"Holy shit!" He said excitedly. Then with out delay he ticked his cock away and headed down to the basemen taking as many notes as he could about the scene and making guesses about thesis single mixtures and concentrations that could have occurred from this miraculous spill

This was amazing. Now he just need to know how long I lasted and how long she would be pliable, then if she would remember. Would she regret it?

He needed leverage. And a way to see how she was doing, was she less pliable? So he decided he'd take a log and check with her every hour. But first he needed leverage

Then he smiled

He headed back up stairs, walking into the bathroom where she showered

"Hey sis. Open up the shower curtain and let me see you" he said casually, expecting compliance, are a short and terse debuff from her if she was feeling back to normal.

Kelly was soaping had body when she heard her brother come into the shared bathroom that was connected between their rooms. Upon his request she pushed open the curtain far enough so that he could see her. Again she acted like it was the most normal thing in the world.

"What's up?" She thought maybe he had a question or maybe he just wanted to look at her body some more. Either way she didn't have a reason to deny his request.

The water ran down her tight and toned body.

It was like those shower scenes in the movies, but it was real! She was just feet away from him, water coursing over the rounded swells of her body, bubbles slowly sliding down the curves of her breasts, and then down her stomach and in between her thighs. He suddenly found himself very curious. But that would have to wait. He had to make sure of his new product first.

He pulled his phone out of his pocket, time to collect some material for blackmail. As long as she was obeying he would get some lewd pictures of her, and of the drug wore off and she was pissed. He would threaten to send these pictures out of she told anyone what had happened.

"Let me take some pictures of you. Pretend your a model for a pornographic magazine for me" he told her, adding the last bit. He didn't just wan t nudes. He wanted dirty photos that would really make her worry. After all she was gorgeous. She might not mind if the world saw that. He needed it to be real dirty.

He lifted his phone up and opened his camera app....

Kelly laughed when he told her what to do.

"God, you're a hornball." She teased him and playfully stuck her tongue out at him. Guess the Internet wasn't enough. It didn't actually bother her. She was actually happy and flattered that he asked her for those kind of pictures and the thought that he would be looking at her to get off made her happy too.

"Just make sure you don't leave your phone laying around so mom and dad can see."

She grabbed the sponge she was using and got it event more soapy and then squeezed it over her chest and let the suds slip down her body. She then started running her hands over her breasts, cupped and lifted them up as she gave them a firm grip all the while she gave the camera a sexy smile.

From there what was supposed to be a simple shower turned into an elicit nude photoshoot and Kelly wasn't holding back either. She was standing, leaning against the wall, laying in the tub, she knew how to use her space! The shower head was removable so she even used that to make it look like she was masterbating... Though she was so excited she probably could have made herself cum.

"OOOH I got an idea! Well, it's actually something I saw online." She turned off the shower, grabbed a towel and started to towel off. Once she was dry enough, her hair was still dripping, she moved over to the sink in front of the mirror. She put her hands on the counter and leaned forward with her ass sticking back behind her.

"Ok, you grab one of my cheeks with your hand and take a picture. Make sure to get my reflection." She instructed. "And really grab onto it."

Once he grabbed her ass she looked into the mirror faking the look of ecstasy. Instead of shifting to a new pose she asked to see the picture. "Ok let's take another one. Try to pull my cheek to the side more so you see more pink, and tilt the phone until you cannot see yourself in the mirror."

They took a few more pictures like that. Kelly's pussy was glistening in the images from how turned on she was. She really did look like a Penthouse model! If gymnastics didn't pan out, at least she could get into erotic modeling.

The release he had gotten a mere 20 minutes ago had not been enough. Of course how was he supposed to know that she would have been so.....professional!

He watched her body in the shower, cock stiffening, as she moved. Sure dripping and sliding over her hefty breasts, slipping between her toned thighs, and water spatterin off her for. Well rounded ass. The she began moving her legs, lifting and spreading. Her pussy was a glistening pink flower. He ached to touch it.

Then suddenly she stopped, but her ideas made him smile

"Thanks sis. You're really good at this, and don't worry. I won't leave my phone laying around" he told her as he watched her towel off. Her hefty tits swayed and bounced as she did so, his erection soon growing uncomfortable.

"What" he half asked as she began to make him grab her. Squeezing her ass. Then pulling at her cheeks, exposing her glistening Pussy and her tight little asshole

"That looks really good" he told her as he snapped picture after picture.

Just as he was about to make a suggestion he heard a car door close

"Oh damnit!" He cursed. He knew his cock was gonna take forever to deflate now

"The parents are home. Thanks for the pics sis. I better get outta here" he told her reluctantly. He gave her ass one last good squeeze

"Later tonight you can come to my room and show me more of these good ideas" he said. Not really thinking. But then again. How would a delayed request work? He wondered as he stepped out the door that led to his room, half limping with his aching hard cock.

Technically, he said if she wanted to. He did not give her a direct order and so her brain did not recognize it as one. Still she just smiled and laughed when he grabbed her ass. It was a shame their parents came home so soon.

Kelly finished in the bathroom and went through the door that lead to her room. She didn't even bother closing the door. If Sam opened his door he would be able to look right at her. In her mind there was no longer any need to hold onto the modesty that she clung to. He already saw her naked and touched her, hell he had pictures of her!

The night was pretty uneventful after that. They had dinner and Kelly acted perfectly normal. There was no trace of shame, or worry. It was like nothing even happened. After dinner she watched TV with her parents, and then went to bed. The drug had worn off, and though she remembered it all, there was still a sense of everything that happened was ok.

He had considered the consequences, made the appropriate safe guards, and he had concocted another beverage for his sister.

He would just hope that she would come to him for a little energy drink after
Her morning run

Or perhaps she would see her tonight.

All these thoughts ran through his head as he toiled away in the basement, cataloging outcomes, manipulating variables, and attempting to recreate the most
Fantastic potion ever made

After hours in the basement he realized how late it was, by the time he headed up to his room everyone was asleep. He crossed his fingers hoping to be awakened in the night. Or he hoped to have a pleasant morning with no.......complications