Author's Note: Welcome to the revised, completed version of this story, originally (partially) published as "Seducing Mom and Dad". I have gone back through and hopefully caught most of the typos. I've also made some mostly minor revisions. The biggest change comes in chapter 3, when Davey and Mandy seduce their mother, Carol. In the original version, Carol was slipped ecstasy without her knowledge, but that lack of consent didn't sit right with me, so in this version she knowingly takes it at the urging of her children. And most importantly, this story is completely finished. All 17 chapters have been written and I will be publishing them a few days to a week apart, so you know you won't be left hanging like when I originally tried writing this story. It just took me a while to figure out how to crack the ending to such an epic story with so many characters involved. Hope you all enjoy the ride!
Davey had no idea how long his sister was standing there watching him. She'd been at college for two years now, so he wasn't used to having her at home. Mandy spent the summer at the Shore after her freshman year, so she'd really only been home during short holiday breaks. But this summer Mandy needed to save money after running up the parental credit card, so she was living back home and working.
Davey knew his parents were out, and their younger sister, Emmy, was almost never home, so he thought he had the house to himself. He was meeting the guys later and decided to rub one out before hitting the road, just in case they met some girls. Davey was so focused that he almost missed his sister there. It was a quick motion in the corner of his eye that made him look over and see Mandy.
"Shit, Mandy, how about knocking?"
"You left the door open. I thought you usually locked the door when you beat off." Mandy sounded amused and invited herself into her brother's bedroom.
"I thought I was here alone. Do you mind?"
Mandy pointedly stared at her brother's cock, steely in his fist, and replied, "I don't mind at all, big brother."
Davey turned red, catching his sister's reference. Mandy had always been brazen so he shouldn't have been surprised, but he didn't expect her to come into his room while he was jerking off. He didn't go soft under his sister's gaze and threw a sheet over his lap.
"You don't have to cover up on my account," Mandy said, standing beside her brother's bed.
"Don't be a perv, Mandy."
"Why? Only boys can be pervs?"
"Hey, I know girls get themselves off these days. I bet you've got a sticky hairbrush handle or two."
Mandy laughed. "I use my fingers if I don't have a toy available."
"Good for you."
Davey put on a good front, but all he could think about was his sister on her back, rubbing her cunt. Mandy was cute. She looked a bit like their mom but had light brown hair instead of being a blonde. Mandy was taller than their mother too, with the kind of curves that a guy shouldn't notice on his sister. Their mom also had nice curves, which also hadn't escaped Davey's notice. Mandy had a juicier butt, but that was because their mom had become a workout fanatic in the past year. Every morning, she was either out running or at the gym taking a spin class. Mandy was only 21 and active. She didn't have to work that hard to keep her trim figure. She was also a couple inches taller than their mother, who was only about 5'3".
Mandy flicked her long chestnut hair back over her shoulder and sat on the bed beside her brother. Her eyes kept going back to where his erection tented the sheet. She didn't quite consider herself a slut, but after dating the same guy for the last two years of high school, Mandy had enjoyed playing the field at college. She'd been with her fair share of guys, always older, and her younger brother compared well. She'd caught him jerking off once before, but when Davey scrambled to cover up then Mandy left his room laughing. She didn't get such a close up look at his dick. Now she wished she'd paid more attention. It was okay. She could make up for lost time.
"So... what are you jerking off to?" Mandy asked.
Davey's blush deepened, if that was possible. It was bad enough that his sister caught him jerking off and wouldn't leave him alone, but now she was getting really personal, asking questions he would never—could never answer. He refused to make eye contact with Mandy, but that meant he kept glancing at her chest, and he couldn't help noticing he peaks of her nipples poking through the thin material of her off-the-shoulder blouse. He did not need to see his sister's nipples right now.
"Go away," he mumbled.
"It's okay, Davey. I know what you're up to. I've known what a while now."
His eyes went wide, and he finally did look at his sister. Her emerald eyes sparkled, and her smile was as wide as he'd ever seen it. Did she really know? How could she? Davey tried to think of a way to escape, but he wasn't getting up while his prick was so hard.
"Mandy..."
"I get it, Davey. Mom's hot. If I was you, I'd be jerking off to her too. But I don't know if I'd be stealing her panties."
"It's Dave, remember?" he corrected by reflex. Davey had been trying to transition to the more adult 'Dave' for a while, but his family struggled with it. He knew his sister in particular still called him Davey just to annoy him.
"Sure, Davey," she snickered.
Mandy reached behind her brother and snatched the panties from where he'd tried to hide them under a pillow when she came into his room. Davey wasn't nearly as slick as he thought he was. It was a frilly little pair of white panties, with a wide lace band at the waist, and not much to cover the butt. Mandy knew their mom had nice taste in underwear because she did too, and their mother had never discouraged her from getting the good stuff.
Davey grabbed for the panties his sister held aloft, but she snatched them out of his reach. He wasn't thinking, he just dove for the panties, jumping at his sister. Mandy fell back onto the bed and Davey landed right on top of her. The siblings squirmed together as they fought over their mother's panties, until Davey realized his very hard cock was grinding right into his sister. He froze in place.
"It's okay, Davey. I kinda like the way it feels. You don't have to stop."
Mandy did indeed enjoy the feeling of her brother's big cock rubbing against her bare thigh. Her cut-offs were very short, giving them a lot of skin-on-skin contact. They both had hands on their mother's panties and they held hands through the thin silk. The siblings stared at each other, both breathing hard, and Mandy leaned up and kissed her brother. Davey didn't hesitate, kissing her right back. She flicked her tongue at his, and Davey responded hungrily.
Davey was so horny he didn't think. He kissed his sister hard, like she was any other hot girl. Her tits were pressed against him and his hard-on pulsed against her leg. It was only when reality smacked him in the face that Davey stopped himself and pulled back. This was his sister he was kissing like that. When he looked down on Mandy, her freckled cheeks were just a flushed as his.
"Shit, sorry Mandy." Dave rolled off his sister, surrendering his mother's panties. He scrambled up to the head of his bed, away from Mandy.
"I'm the one who kissed you, remember. And I'm not sorry. It was nice. You could use a little work, but you're a good kisser, little brother."
"Mandy, come on. Stop. This has gone too far."
"Not yet, but it will, Davey. You've been perving on Mom for years. I've seen the way you look at her."
"You're crazy!"
Mandy held up the panties. "Am I? It's natural, Davey. A lot of boys have a thing for their mothers. It's the oldest story in the book. It's so old the Greeks even wrote about it."
Davey was silent. He knew he'd been found out. The only thing he could do now was try for damage control. He stared at his sister. She did look so much like their mother—only Mandy's tits were probably bigger. Maybe they were just perkier. Davey wasn't sure. Mandy was staring at him queerly. It gave him a funny feeling in his stomach. It was the way he'd wished his mother would look at him all those time he was jerking off to her.
Davey's thing for his mother went back a few years, even since his best friend Jaxon confessed had a crush on her. Jaxon would go on and on about how hot she was. Davey was used to friends crushing on his sisters, but he didn't expect it for his mother. Jaxon kept telling him she was the ultimate MILF. Jaxon always said, If I had a shot with Carol, I'd fuck the shit out of her, man. You're so lucky you get to see her every day. Do you ever catch her coming out of the shower? I'd make it happen, man. It worked on Davey's brain, and soon he was seeing his mother just as his friend did. Seeing his mother in her tight workout clothes, or in bathing suits on vacation didn't help. Beating off to fantasies of his mother became a regular thing for Davey, but he thought it was his dirty little secret—until now.
"You don't think she knows, do you?" he asked.
"Mom and Dad are oblivious. They're way too into their own lives to notice anything like that. Mom would never think her sweet little Davey wants to fuck her brains out, anyway."
"Mandy!"
Mandy laughed. "It's true. Not that you're so little anymore. It's a shame Mom hasn't noticed. I have."
"Mandy... What are you doing?"
"From what I felt, you could use some relief. And this is your lucky day, baby bro."
"Come on, Mandy. Don't."
