Accidental Nympho Sister

As Sara nursed on her Mother's tits, she wasn't sure if that was possible. But this was a welcomed start. Her Mother's hands moved around, and as Sara nursed on the hard nipples, she felt her Mother reaching forward to rub her tits in return.

Could it be? Was Mom enjoying this too?

***

Despite her worries, Sara did her normal hostess duties as the party guests would expect. There was a last minute option to leave home while the party happened, but that was out of character for her.

There was no way she'd ever let her family down. She loved everyone too much to hide because of a medical issue. Especially since she'd been away from everyone during her first year medical residency.

The party was the same as always. Uncles, Aunts, and cousins from all over had come to visit. Mom did most of the schmoozing. Dylan was in charge of food. Sara was tasked with service, which she enjoyed doing with her beautiful smile and charm.

Wearing a cute yellow dress, Sara went around the living room to make sure everyone was having a good time and was properly fed.

Through it all, she had a chance to catch up with distant relatives and people she only saw a few times a year. The Aunts and Uncles showered her with the usual compliments:

'You've become so beautiful!'

'You remind me so much of your mother when she was your age.'

'A doctor? Brains and beauty. A dangerous combination.'

But for all the fun, Sara's demeanor made a drastic change when her brother stepped into the living room. Though he was just coming to socialize with family, it felt different. Sara had always been the 'good girl' at the family function, but as Dylan chatted and laughed, Sara's thoughts were far from good.

Crazy thoughts ran through her head: 'Take him upstairs and fuck him. Yes, even with the family party going on. Nothing will make me hotter.'

She realized the thoughts were making her pussy wet as they repeated in her mind, growing more insistent with each repetition.

"Are you okay?" Mom whispered in Sara's ear.

Sara snapped out of her trance, and she turned her attention towards her Mother, who was dolled-up like the perfect MILF.

"It's happening," Sara whispered. "I'm really sorry."

The only reason Sara apologized was because a few hours ago, they had engaged in another nursing session. It happened in Mom's bedroom while Dylan was in the shower. Mom had exposed both of her luscious tits and allowed Sara to suck on them for a good 10 minutes straight. Mom's nipples even turned red.

"It's not your fault," Mom replied. "What are you feeling?"

They both looked around. The coast was clear and the living room was loud with chatter and laughter.

"I want to take Dylan upstairs to fuck him."

Mom sighed. "Will a cold shower fix it?"

"Unlikely. God, I've never been so desperate in my entire life."

"Maybe you should handle it already," Mom said after a long pause.

"Huh?"

"I remember what it's like being your age. Hormones are raging. Things are confusing. I've tried my best to help, but nothing is good enough."

"Are you suggesting that I fuck my brother?" Sara asked.

"I'm not saying that either."

"Then what are you saying?"

Mom looked around. "Sex is an indulgence, much like food. If I have a slice of delectable chocolate cake, my cravings are satisfied and I'll stop thinking about it for a while. Does that make sense?"

"It kind of does."

Sara thought about her brother: 'Mom is a genius. I want that cock so badly. I want to fuck him while the party is happening. Everyone would be oblivious to the fact that I'm an undercover brother-fucker.'

"It's a guilty pleasure," Mom said. "I'll never fully condone it. But -- and this is very important -- you know that I have a reputation to uphold. Things have to run smoothly at my parties. The family depends on me."

"Everyone looks content right now."

"At the moment. If you and Dylan disappear for 15 minutes, then I would be okay with that. But I'd need you back immediately. Dylan too. Please be gentle with him."

Sara's eyes widened. "Oh my god, Mom."

"Don't give me that. Besides, isn't this part of Dylan's job?"

***

After dragging her brother up the stairs, she was in complete control of the situation. She decided that Dylan's room would be the best place. She wanted to fuck on his desk. Just like in her naughty fantasies.

"Mind telling me what's going on?" he asked.

Sara locked the door. "It's time for me to be honest. I need to fuck."

"What?"

"I'll give you the details later," Sara told him. "The short version is that Dr. Ledgard's experiment messed me up. Badly. I knew it was possible, I just didn't believe it."

"Believe what?"

She lifted the front of her dress. "This."

With her dress held up with one hand, she used her other hand to pull her panties aside to reveal her pussy. It was cleanly shaven and the clitoris was swollen while protruding.

Sara dipped her index finger into her entrance. She held her finger out, showing her brother a thick and clear liquid consistency.

"Holy shit," he gasped. "Is that the source of those weird signals coming from your body?"

"Yes, I haven't been right for the past two days. My pussy is killing me."

So... umm... why are you showing me?"

"I'll explain the whole thing later," she sighed. "But right now, I need you to bend me over the desk. Fuck me -- like our lives depend on it."

"What the..."

"Dylan, look here," she said, rubbing her labia. " It's an emergency. I want you in me, I NEED you in me!"

"But... why me?" Dylan asked, worried about the potential implications of doing something so taboo.

Sara swallowed her pride. "I need your cock. Yours specifically. I've been thinking about you like crazy. It's freaking me out."

"You mean, because of the experiment, you've..."

"Are you interested or not?" she said firmly.

"I... ummm... sure... How should we start?"

Sara brisked over to him, grabbed him by the dick, and pulled him to the desk. She yanked his pants down and his semi-erect penis was almost ready to go. The horny little bastard was easily aroused by the sight of her pussy, she thought. At least she was under a spell; Dylan had no excuse.

"We've got to be quick," she said, stroking her brother's cock. "Mom needs us back as soon as possible."

"Does she know?"

She could see the conflicting emotions play across his face, lust winning out, as she continued stroking.

Her inner voice told her: 'Go ahead. Tell him everything. My younger brother needs to know. It's about time he knows what I really am.'

"I've told Mom everything," Sara confessed in a low purr. "Mom knows how badly I want to fuck you. The truth is, Dr. Ledgard's research accidentally made a mother and son have sex. I didn't believe it. Now I'm the next step in the research.

She continued, "Mom tried helping me. She thought she could alleviate these nymphomaniac tendencies by showing me her amazing set of tits. She let me suck on them. That's right, I nursed on Mom's tits and pulled her nipples with my mouth. I think she likes it, since she fondled my breasts as well."

He was dumbfounded with arousal. "You and Mom? Nymphomaniac?"

"I know, shocking. I can explain more later, but right now I need to get fucked."

Sara was under the influence of the frequency waves and she couldn't care less that the whole family was downstairs, having a nice, wholesome time together. Actually, the risk was turning her on even more. These were the nymphomaniac tendencies she had been warned about, and now she was loving every second of it.

To get him fully erect, she grabbed his neck and pulled him in, planting a big kiss on his lips. It was gentle at first, before turning rough and slipping her tongue inside. Their tongues wrestled for a good minute. All the while, she could feel her younger brother throbbing in her hand.

She pulled back and released him. "You're ready."

It was amusing seeing Dylan so speechless, cock freed, and in admiration of her attractive body, knowing they were about to fuck. She had always been the leader in their sibling relationship, now it was heading in a new direction.

Sara bent over her brother's desk, presenting her rounded ass. That way, her little brother could fuck her easily while standing. Her juices were running down her long, shapely legs. Her pussy lips were swollen and inviting, begging to be filled with his achingly hard cock.

"Your ass is amazing," Dylan said, sticking his index finger into her vagina.

"Just fuck me already, please."

Sara was over the edge and didn't care that it's wrong by society's standards. All she wanted was to be fucked by her brother. Sure, it was nice sucking on Mom's tits, but that did nothing to satisfy the intense craving between her legs. Only her brother could do that, with his thick penis.

She felt her pussy being spread while she opened her legs for him. Inch by inch, her wet cunt was being entered. Despite her tight pussy, it was an easy process because of how fucking aroused she was.

"Oh yes!" Sara moaned, before realizing that she needed to keep her voice down.

Dylan pumped faster, with an unrivaled force. "Your pussy is amazing. Fuck. I can't believe I've been missing out on this."

"Just keep it quiet," she hissed.

While she was being pounded from behind, her submission to her brother was now complete, with her pussy being ravished. Her brother teased her by pulling her hips and bombarding her with his thrusts, slamming his balls against her pussy lips and gliding his cock through the warm folds of her pussy walls with incredible speed.

It was everything she needed.

Even though Sara was lost in what her brother was doing -- and doing so well -- she heard noises in the hall. She knew the bedroom door was locked, but they still shouldn't be heard.

"Stop, Dylan, there's someone in the hall," she whispered.

Dylan stopped for a second. "They're in Mom's room. I'll go slow."

Sara didn't have the willpower to stop her brother; instead she buried her face in the pile of papers they used to record her data and she pushed her hips, to encourage the fucking to continue. Dylan's cock was gliding through her canal, slowly retreating back, leaving only the head at her entrance, then going all the way in again, filling her insides.

Her inner voice re-appeared: 'Finally, I'm a happy girl. All I need is his cum. His cum inside me. Then I can reach between my legs. Scoop it. And slurp it all down.'

The thought of Dylan's cum pumping into her eager cunt had Sara licking her lips. Her body demanded more from her brother. Her body needed to be filled with his seed, to have his cum leak between her vaginal walls and stream down her legs.

After a few minutes of slow, sensuous fucking, the incestuous couple heard footsteps heading down the stairs. Without a word, they sped up their lustful attack on each other and Dylan was again plowing into her with wild abandon.

"They're gone," Dylan said, pumping harder. "You like it harder, don't you?"

"Yes, yes, yes!" she cried.

He groaned, "Where can I cum?"

"In my pussy," she said. "I want to eat it right after."

"Really? Oh... fuck!"

That sent Dylan over the edge as he pounded with all his might, making Sara cry. Sara's tears increased as she approached her earth-shattering climax at the same time as her brother. They both came and she felt her pussy flooded with her brother's load. She could feel their cum mixing and intertwining to form a cum cocktail during the family party, which would be her secret treat.

"What now?" he asked, kissing her neck while still buried within her.

She smiled, face laying on the table. "A snack to recover my energy."

Their bodies separated and the still-sensitive head of the cock plopped out her clinging lips. Sara reached between her legs and inserted two fingers to scoop the cum which dripped from her well-fucked hole.

Before she could complete the mission, she heard the sound of a key slipping into the knob, unlocking the bedroom door.

Sara's heart nearly stopped at the sound of the locked doorknob being twisted and turned. Then the siblings heard a key slip into the lock as the knob now turned without resistance.

Only their Mother had the bedroom key, and in a flash, she entered the bedroom and shut the door, locking it once again.

"You two were almost caught," Mom fumed. "There were inquiries about strange noises in here. I told your Aunt that you had a bruised rib from a recent skiing trip."

The siblings stood frozen as Mom approached them while they were still exposed after having finished fucking.

Sara pulled her skirt down and stood upright. "Mom, you shouldn't be here."

"We have a party to host," Mom countered. "And the noises you two have been making are unacceptable."

Dylan blushed, with his penis still out. "Sorry."

"Don't be sorry," Mom replied. "Get cleaned up. These smells are potent and the last thing we need is for anyone to notice."

"There's plenty of tissue," Sara noted.

Mom shook her head. "No, that won't do. I can smell both of you. The fragrance is strong, since you're both young. If you walk down the hall, others may smell it."

"What do you suggest?" Dylan asked, with fluids dripping from his cock.

Mom sighed. "The things I do for my family."

The siblings froze in place, stunned, as Mom dropped to her knees.

Sara was in awe of her Mother, who lifted her dress and went to work eating her pussy. It was her first time being eaten by another woman and it was spectacular. Sara closed her eyes and tilted her head back as the cum cocktail was being sucked out of her little hole.

It was pleasure Sara never knew she needed. Mom darted her tongue inside her trembling daughter, cleaning every inch and centimeter, as deep as she could go. When she was satisfied that Sara's cunt was cleaned, she pulled away, giving her daughter a brief visual inspection and nodded to herself.

"You're so good at that, Mom," Sara whispered.

"Not that you should have known," Mom said, licking her lips. "Dylan, you're next."

Dylan stepped forward. "Whatever you say, Mom."

In an instant, Mom turned her attention toward the wet cock, taking it into her mouth to suck the excess cum that lingered. It was more of a maternal duty than anything else. But it was just as explicit as any porn scene. Her lips wrapped around the shaft and she gave hard, powerful sucks.

As she watched her Mother go down on her brother, naughty thoughts arose in Sara's mind: 'There it is. Here's your chance. Mom deserves a little relief. And I want a taste. I bet she's delicious.'

Sara got on her knees, right behind her Mother, and lifted the back of her dress. She pulled the panties to the side and pressed her lips there, making Mom squeal for a moment.

"What's gotten into you?" Mom asked, spitting the cock out of her mouth.

Sara darted her tongue in her Mom's asshole, then brought her tongue down to get a taste of pussy, lapping her tongue inside. Mom seemed rather aroused (and tasted like it too.) When she moved around, she kissed her Mother on the lips. Mom was hesitant at first, but went along with it and their tongues wrestled with family fluids.

After a few moments, Mom broke the kiss with her daughter and touched Sara's cheek tenderly. She kissed Dylan on the tip and stood.

"Alright, my two darlings, that's enough," Mom said. "Get dressed. Downstairs in one minute."

The siblings dressed quickly, checking each other for any telltale signs of their incestuous coupling. Neither of them minded the saliva as they wore their clothes. It would dry soon enough. Dylan was content with just pulling his pants up. Meanwhile, the ladies shared the mirror and fixed their dresses and hair, not to mention making sure their lipstick hadn't been smeared.

Dr. Ledgard put the final touches on the report while sitting in the lab. Other researchers were there, monitoring heart activities and brainwaves from the two subjects.

In a glass room, which the researchers were focused on, Sara was riding her brother on a bed they had set up. The siblings were naked as they had intense sexual intercourse with lust-fueled abandon. They were bashful at first, as anyone in that situation would be, but once they got started, they were unstoppable.

"You're a true genius," General Hamilton said, observing the vigor of the youthful coupling. "I've always had faith in you, this is a job well done. I'm recommending you for a promotion and a generous pay raise."

"I don't do this for money," Dr. Ledgard replied.

"No? Then what drives you?"

"Knowledge," the doctor responded, looking at the incestuous coupling once again.

The siblings finished their strenuous loving-making session and Sara collapsed onto her brother, with her breasts resting on his face. Her pink nipples were hard and the brother took it upon himself to suck on them.

When the researchers called for an end to the session, Sara climbed off her brother, and a trail of thick fluids leaked from between her legs. Sara cupped her buzzing pussy, catching the fresh cum, wiping it with her fingers, then brought it to her mouth. She licked her fingers clean.

Sara knelt before her brother and cleaned with her mouth and tongue. According to daily reports that Sara and her brother had submitted, this was routine for them. Foreplay, sex, and 'oral cleanup.' Their mother, it seemed, had helped ensure that everything was under control. Mom was the glue that held this experiment together.

The End

Special contributions from the great gonzo437a and amachi.

vote / comment / follow