Dirty Mom, Dirty Sis

**This story contains brief references to m/m sex. If this isn't your cup of tea, feel free to keep scrolling. Thanks.

Elaine had no reference for what she was going through as she sat behind the wheel of her SUV. Matt, her son, was waiting for her to drive away. He was disheveled and sweaty, but no matter how much he smelled like a boys' locker room, his mother couldn't deny how insanely cute he was in any condition. His T shirt was damp and his bare legs looked slender but so toned in the shorts he'd put on for soccer practice. She'd always been aware of how the girls in his class and even the mothers of his friends could see how cute he was, but Elaine was his mother and now she found herself trying to act like nothing was wrong while her pussy flushed hot and wet just being next to him.

The divorced mother of two had no idea where this was coming from. It happened the first time a couple of weeks earlier when Matt came into the kitchen simply to dry dishes after she washed them. He'd been standing close while they made some small talk. That's all it was. Just simple, everyday mom and son stuff, when Elaine felt her pussy suddenly flush hot and wet and she found herself looking at the side of Matt's face and wondering what his lips would feel like pursed around her throbbing clit.

The voluptuous, blonde thirty-six year old ended up fingering her aroused pussy twice before being able to fall asleep that night. By morning, she tried to put the incident as far out of her mind as she could, but her body's response to her son was out of her control and it kept happening again and again. She had no idea what was happening to her. She hadn't felt herself get wet just being near someone in a very long time.

Matt was twenty now, and fortunately, he had no idea of the turmoil he was causing his mom. Elaine passed it off as a simple, chemical reaction to male pheromones, but that didn't explain why she found herself imaging his lips on her pussy while simply watching him talk. Or times like now, when he was wearing his soccer shorts and she followed the taper of his slender, muscled thighs up to his crotch.

Matt had always been special to his mother, but not in a way that explained the dripping heat in her slit whenever he was close. Sure, he was turning into a wonderful, gorgeous young man, but he was her son. She was supposed to have a genetically wired filter to make her immune to his erotic appeal. Maybe she was just the victim of faulty wiring. Or maybe she'd just gone without sex for far too long. But if that were the case, why didn't she get this unmentionable reaction when she was around anyone else?

"How was practice?" she asked, stalling to give herself another chance to look at his sinewy thighs and nicely packed crotch.

"Okay," he shrugged. "We'll probably lose on Sunday, though. Our defense just isn't strong enough."

Matt played soccer for a small, private college not far from where they lived. On Sunday, their team would play against a bigger school.

"I know you'll do your best, baby."

Matt looked at her and smiled. His eyes were glowing but surprised. His mother never called him baby. Honey or Sweetie were her usual terms when she didn't use his name. 'Baby' had just slipped out and she was surprised to see how much he seemed to like it. He then did something that made the broiling heat in her pussy worse. His eyes made an obvious sweep down her neck to the exposed cleavage of her lush, double D tits. She was wearing a light weight sundress that showed off her melons beautifully without looking too scandalous. The hem was loose and not too short, but in the car it rode higher on her legs.

Elaine carried a bit more weight than she had in her teens and twenties, but it packed itself quite nicely around her ass, thighs and tits. Combined with her pretty face and buttery blonde hair, she could've been a fertility goddess in an ancient myth. Her appeal to males had always been deep, which was how she ended up being the mother of a twenty year old at thirty-six. Her second child, Matt's sister, was now eighteen and had a different father, making them half siblings.

Elaine had never been married to Matt's father, but she had been married to his sister's father for a couple of years. Both dads were always good about paying their child support, but neither of them stuck around to be part of their kids' lives. That never bothered any of them, though. They had a close-knit family of three that was always happy and normal. Until recently. Elaine now felt like she was carrying a filthy secret inside. Something sordid and sinful: the lust of a hot, young mother for her sexy son.

Matt was blonde like his mother, with longish hair and a slender but athletically toned body. He'd always been the kind of boy mothers trusted around their daughters, so he always seemed to have female friends, making his mother wonder sometimes whether or not they were girlfriends. He did have girls in his room many times, but Elaine had never seen or heard anything out of order. She'd never walked in on him making out with a girl when they thought they had the house to themselves. Having his younger sister around the house probably kept him from taking too many chances with girls when they were at home.

Matt was a fiercely protective big brother, and he'd bloodied a few lips and noses when boys teased his sister about being chubby. As a result, Dani, as everyone called her, was enamored with him. And Matt was just as likely to take his little sister along when there was a group going out to a movie or party. Just as often, he was known to take his sister and groups of her friends out places before any of them could drive. Consequently, he was probably the only guy his age in their town that had been on mall shopping trips with groups of girls his sister's age. Yet he never uttered a word of complaint. If anything, he seemed to like taking the girls around, and his mother was proud of what a model big brother he was.

Dani didn't look much like her mother or brother, favoring her father's darker haired looks. She was a beautiful girl, but not in the more obvious way her mother was. She did have a pretty, pixie-ish face, with long, medium brown hair and a body that remained on the chubby side no matter what she tried. She had thick legs and ass, with dainty B cup titties that were pert and shapely, but what she thought were too small for her body. There was a slight taper to her waist, giving an hourglass effect, but she still had a few tummy rolls that bothered her.

Over these recent weeks when Elaine was having her unmentionable reactions to her son's presence, she wondered a few times if his sister could have the same reaction. But she put the idea down as silly. Dani wasn't a sexual creature like her mom. She didn't have the same boldness or self-confidence when it came to males. Not that this had always worked in Elaine's favor. She was, after all, the single mother of two kids with different fathers, neither of which she had a long term relationship with. Yet she wouldn't change a thing. Matt and Dani were the best kids a mother could hope for.

But it wasn't normal for Elaine to feel nervous or tongue-tied around a guy like she was that day in her SUV with Matt. She blushed when he took note of her calling him baby, and then felt her pussy heat up unbearably when he gazed at her half exposed tits like he didn't care about getting caught. His eyes finally rose back to her face.

"I like making you proud, Mom," he told her. "But that's easier to do if we win."

"Oh, ba ..." she cut herself off before saying baby again. "Uh, Sweetie, I'm proud of you no matter what."

"I know. I just like seeing the look on your face when we win."

This was unexpected. She didn't know he paid that much attention. Casting one more glance between her son's thighs, Elaine started the engine and drove out of the parking lot. They made small talk on the way home but Elaine's pussy was driving her crazy. She shouldn't have waited so long to connect with one of her semi-regular male friends to get some cock. She was afraid the car would reek of wet pussy long before they got home.

Elaine tried to distract herself with a change of subject and told Matt she was glad Dani was going to the same college in the fall. As rough as high school had been on the girl, college could be worse and she was glad Matt would be close by to look after her.

"You're such a good brother," Elaine said. "She's always been so shy and sensitive, and you've always taken such good care of her. I hope she won't end up getting in the way of you meeting the right girl at school, though."

But even as she heard the words coming out of her mouth, Elaine suddenly hated the idea of her son getting into a serious relationship that would take him away from her or Dani.

"That won't happen, Mom," the boy reassured her. "Dani's way more important to me than any of the girls at school." He paused a couple of seconds. "Just like you."

Normally, Elaine only indulged thoughts of being her son's woman for a few, brief moments at a time, but as she drove closer to home the idea stayed with her all the way.

At their modest house, Dani was in the living room watching TV when mother and son went in. She was dressed as usual for when it was just family at home, in a pair of light cotton shorts that barely covered the full, thick cheeks of her rounded ass and a low cut tank top with spaghetti straps. Without a bra, Dani's pert, cupcake titties were nearly exposed. The girl wouldn't dare wear anything that revealing outside the house, and her mother never said anything about her dressing that way in front of her brother. She thought her daughter should be proud of her beautiful body.

Sure, Dani was thick and curvy, but without tits that matched the rest, yet Elaine knew the girl was highly appealing to anyone who appreciated a girl with firm flesh on her bones. And there were times the girl's mother envied her much smaller, perky tits. Elaine's were so big and heavy it often felt like they were in the way. But the looks they drew from her son made her happy to have them even though she'd spotted him looking at his sister's tits the same way just as often.

Matt headed for the living room where Dani was sitting while Elaine went the other way toward the kitchen. But she stopped to admire her son one more time. She watched him approach his sister and stood nearby while he took a very obvious look at the younger girl's exposed charms. Dani blushed and looked shy, but couldn't suppress a wide grin in response to her big brother's attention.

"God, sis, you look amazing," he said, trying to keep his voice low enough to keep their mother from hearing.

But Elaine did hear, and she also noticed the way her daughter's nipples began to swell and dent her top.

"Awww, Matt, you're always so sweet to me. I wanted to look nice for you when you came home from practice."

As affectionate and devoted as the siblings had always been, Elaine had never heard them talk quite that way before. It almost sounded inappropriate, but that was the impression of a woman who'd been getting wet just being around her son. Maybe she'd been wrong about Dani. Maybe the girl actually did have similar feelings for her brother.

"You always look beautiful, as far as I'm concerned," Matt said, still whispering.

Dani giggled softly. "You always say that."

"Well, it's always true."

"Oh god, Matt, that's why I love you so much."

"I love you, too, sis."

Elaine slipped into the kitchen before one her kids looked over and caught her eavesdropping. It wasn't like she hadn't heard her son and daughter say I love you before, but they were whispering and Matt's compliments were out of the ordinary for a brother and sister. The tone they were using gave their mother goose bumps.

Elaine started to pull things together to make a quick spaghetti dinner with a salad. Dani came in a few minutes later to help. She was smiling to herself and looked a bit flushed, but her mother kept her observation to herself. Half an hour later, the family of three had dinner together. Elaine tried to secretly watch her son and daughter for signs of anything out of the ordinary, but everything seemed normal for a brother and sister who were closer than average.

The rest of the evening found Elaine in a daze. Matt came into the kitchen and dried dishes while she washed them and put his mother in the same, tingling condition all over again. He had showered and changed into a fresh pair of shorts and T shirt, and she didn't understand how he could affect her this way. Now it was even more confusing because of the weird feeling she couldn't shake about the way he and his sister had been talking.

After the dishes were finished, Matt put his drying towel on the counter and turned to his mother. He was smiling and looking at her with a certain gleam in his eyes. Elaine's breath caught and her nipples erected instantly. Matt glanced quickly at the nubs denting her dress front.

"Mom, I hope you know how much Dani and I appreciate you," he said, surprising her.

"Why, Sweetie ..." she didn't know what to say.

"We don't always show it, but we know how much you do for us. How much you give up for us. I know Dani loves you for it just as much as I do."

"Oh, Matt, baby ..."

Elaine's nipples were swollen and throbbing as much as her pussy, and now she wanted to cry tears of love and joy. But then Matt put his arms around her and hugged her tightly. She hugged him back just as hard, feeling her body heat up at the way she purposely crushed her big tits against his hard, young body. His groin was pressed against her lower tummy and she could tell he wasn't wearing anything under his shorts. By the time he planted a quick kiss on her lips and let her go, her panties were soaked but she felt so loved she didn't care.

After Matt left the room, Elaine decided to take a long, hot bath. It was a relief to peel off her dew soaked panties, but once in the tub, she quickly got busy with her fingers stroking her needful pussy and twisting her sensitive nipples. She relived Matt's wonderful hug as she brought herself to a climax that made her body rock so hard she splashed bath water all over the bathroom floor.

Before she finished bathing, though, she took her time to shave her legs and pussy. She'd neglected her mound for a while since there was no one on the immediate horizon to see it, but it felt good to shave herself down to nothing but a pencil thin landing strip of blonde hair atop her mound. It made her smile to wonder what Matt would think of his mother's carefully groomed pussy if he could see it. It was terrible but so intoxicating to think about. Knowing what kind of boy her son was, she knew he'd go out of his way to make her feel beautiful.

Elaine had a collection of Matt's old sports jerseys she wore for bed. She put one of them on along with a fresh pair of panties and went downstairs to find her son and daughter sitting on the couch watching a movie on TV. They were sitting close and holding hands. It wasn't unusual for them to sit close or even snuggle in the cooler weather, but the hand holding was out of the ordinary. She pretended not to notice and took a seat on the empty end of the couch. She watched the movie with them until her eyelids started growing heavy.

Elaine dozed off to sleep just a couple of feet away from her kids. Despite her nagging suspicion there was something off about the way they'd been holding hands, she felt happy to be with her small family. There was something endearingly sweet about their extra closeness. They were all home and safe and among people who loved them. She didn't know how long she slept, but she suddenly became aware of whispering in the same kind of tone she'd heard earlier when she brought Matt home from practice. She kept her eyes closed and focused on keeping her breathing steady so her kids would think she was still sleeping, but her maternal radar zoned in on her son's and daughter's furtive whispers.

"Oh, Matty, it's so hard," Dani whispered with a muted giggle.

"I can't help it, sis. You always make me hard. You're so hot even when you're not trying to be."

"Aw, baby, you're always so sweet to me," she whispered with a sigh.

Elaine felt herself clench when she heard her daughter call her brother baby. Sisters just didn't call their brothers names like that. But she'd had to keep herself from doing the same thing when they were washing dishes together. She opened one eye just a tiny slit to make sure what she heard meant what it sounded like. Sure enough, Dani's hand was between her brother's legs, gently rubbing the long, tubular bulge in his shorts.

Their mother's heart started racing immediately. It was a struggle to keep from gasping in shock. She didn't know how she could ever keep up her charade of being asleep, but she was determined to try. She felt a powerful instinct to put a stop to this forbidden behavior, but then an even more powerful urge to see how far it would go.

She didn't have any idea what to think about what was happening between the two siblings. Could her son and daughter be having sex, or did they have enough sense to confine themselves to a little relatively harmless teasing? Whatever they were doing was going on under her roof, so it seemed like she had a right to know. Then there was the sight of that hard cock under Matt's shorts. It looked impossibly big, making his mother's pussy wetter than any other time that past couple of weeks. And his own sister was touching it!

"I can't believe I get to touch this huge thing whenever I want now," Dani whispered, gazing at her brother with adoring eyes.

Even through slitted eyes, Elaine knew that look on her daughter's face. It was the look of a girl who was hopelessly in love. The mother's heart sank with concern, and more than a little jealousy. She'd imagined her own hand making that same, erotic gesture more than once. Her senses tingled with feeling as she tried to imagine how that rigid tool would feel under her own hand.

"It's all yours now, baby, so you can just touch that dick anytime you want," Matt told his sister softly. "Ahhhh, you really make it feel so good."

Dani giggled under her breath. "I'm glad. I really love your dick so much, Matty. It's the nicest one I've ever seen."

Matt put his arm around his sister while she kept fondling the prominent lump in his shorts. Elaine could now see he was just as much in love with his sister as she was with him.

"I can't believe you're finally my girl," he whispered, slipping his hand into her low cut top from above. He started massaging her braless titties, making her sigh with longing.

"I wish I knew you wanted me a long time ago," Dani whispered back. "Then all our first times would've been with each other."

"I'd like that, too, baby, but the important thing is we're together now and we always will be."

"Promise?"

"Promise." Then he kissed his sister boldly. It was deep and passionate as brother and sister hungrily devoured each other's mouth with their tongues swirling wetly in between. Dani made a whimpering sound and kept squeezing his cock while the hand he had inside her top made a steady circuit across and around her tits.

Elaine wanted to explode but she did her best to just breathe steadily and not move a muscle. It felt like an impossible task. She managed to keep up her pretense while her son and daughter spent a long time kissing heatedly and fondling each other. At the moment, they were so involved in each other she doubted they'd even notice if she "woke up". Finally, though, they broke their kiss.

"God, I love your tits, Dani. They feel so good," Matt told her, still whispering.

"Bet you wish they were bigger. More like Mom's."