NOTE: this is a future-fic, meaning that Bart and Lisa are both over the age of consent.
As he pulled his motorcycle into the driveway, Bart Simpson let out a sigh that he??™d never admit to making. Just a few years ago, he??™d been Hell on skateboard wheels, sending everyone in town diving for cover as he raced home from school.
That was before Homer had died, keeling over in Moe??™s Bar just over two years ago. Thanks to the levels of his beer and donut consumption, Doctor Hibbert wasn??™t sure whether it was his exhausted heart or his overworked liver that had killed him. Working at the nuclear power plant for decades without a single promotion had left them with no savings, and working for Burns had left them with the state-required minimum health and life insurance. If Ned Flanders hadn??™t been kind enough to rally the church members for contributions, Marge would have had to go into debt just to pay for Homer??™s funeral.
Marge had spent the funeral and wake cuddling toddler Maggie, and accepting condolences with as much dignity as she could muster while crying almost non-stop. Bart and Lisa had spent the funeral and wake planning how they were going to keep from losing the house.
Bart had dropped out of high school, and gotten a job working construction; hard, heavy labor that paid enough to keep them all fed and clothed. On the bright side, his days as the terror of Springfield Elementary and Middle School had given him some useful skills in demolition ??“ his boss had just offered to put him through specialist training. It had also given him some impressive muscles; he could have almost any girl in town these days, if he had the time or energy.
Lisa had tutored him through getting his GED (she??™d insisted), then taken a heavier courseload so she could graduate early. Besides applying for every college scholarship in existence, she was also tutoring what seemed like half the kids in school for extra credit and cash.
These days, they both always felt like they were sprinting in place; tired, stressed out, and constantly worried about everything. If they hadn??™t discovered a way to blow off steam and relax, their heads might have exploded!
Bart slammed the front door behind him, then dropped his backpack and kicked off his heavy boots on the floor next to the door. Striding into the kitchen, he found six year old Maggie sitting at the table and coloring. Dropping a kiss on top of her head, he then greeted Marge with, ???S??™up, Mom????
???Welcome home, Bart!??? Marge said cheerfully, turning away from the stove. ???Dinner should be ready in about an hour.???
???Cool. I??™ll go take my shower, then.???
???Alright, dear. See you at the table.???
Bart ruffled Maggie??™s hair, before heading for the stairs, thumping loudly as he could in his socked feet. Stopping in his room just long enough to strip, he strolled naked across the hall to the bathroom he shared with Maggie and Lisa, enjoying the feel of the air on his bare skin, and the sensation of his long dick swinging against his thighs.
Locking the bathroom door behind him, he looked to the right and smirked. Lisa was already there, sitting on the closed toilet lid with her head tipped back and eyes closed, while she had one hand under her Tshirt, playing with her tits. Her panties were on the floor, so with her skirt pulled up to her hips and her legs spread wide, Bart had a great view as she plunged three fingers in and out of her pussy.
???Impatient today, huh???? Bart snickered, even as his cock started to harden.
Lisa??™s eyes opened, and she glared at him. ???I??™ve just spent two hours trying to get Ralph Wiggum to understand math. Hurry up and fuck me.???
Bart grimaced in sympathy, and hurried to turn on the shower. Waiting for the water to warm up, he pumped some liquid soap onto his hand as improvised lube and hurriedly jacked his cock to full hardness.
Lisa didn??™t even wait that long; dropping her top and skirt on top of her panties, she stepped into the shower, hissing a little at the cold water but loving the way it felt on her overheated body, and made her nipples hard as Bart??™s cock. Lisa leaned forward to brace her hands on the far wall, and arched her back, pushing out her hips invitingly, and shivered in pleasure as the cool water hit her back and trickled down the crack of her ass to tease at both her openings.
Puberty and her vegetarian diet had been good to Lisa. While only medium height, she had a flat stomach and slim body, a tight ass and round breasts that were high and firm despite their D-cup size. Bart loved groping them when he fucked her from behind, and how they bounced violently whenever she rode his cock. When they fucked face to face, they both loved the way her tits rubbed against the hard wall of his chest.
Unlike the bathroom attached to the master bedroom, the shower stall in this one was tiny, so Bart could stand in the open doorway of the shower stall to avoid the still-cold water. Grabbing his sister??™s hips, he immediately rammed his dick home, burying himself balls-deep in Lisa??™s pussy. Lisa covered her mouth with her hand to muffle her shriek of pleasure, and Bart let loose, fucking her hard and fast and filling her pussy right to her womb with every stroke.
???Yeah, Bart, that??™s it, give it to me, my pussy??™s been hungry for your cock all day,??? Lisa moaned.
Of the two of them, Bart always thought HE??™D be the dirty talker. Who knew?
???Slam it in hard, Bart, you know how I want it, push it in deep.???
Lisa was hot and wet around his throbbing dick, and Bart grunted as he pounded into her. Wanting her to come fast, he reached under her belly and skillfully rubbed her clit. Lisa gave another muffled shriek, and her pussy clamped down on him so hard it nearly hurt. Bart gritted his teeth and growled from the effort of holding back his climax ??“ Lisa??™s pussy was still almost as tight as it had been the day they??™d gone out to the treehouse to keep from alarming their mother, started screaming at each other and finished by tearing at each other??™s clothes and going at it like animals – as he rode out hers. Feeling her come on his dick always drove him wild, but they were already running out of time, and they couldn??™t wait for him to recover and get hard again.
Lisa slumped forward against the wall, and Bart stepped forward into the downpour. Seizing the chance to finally wash off the grime and sweat from a long day on the site, Bart quickly lathered up his chest and arms.
Catching her breath from her orgasm, Lisa leaned against the shower wall and watched her brother appreciatively.
While he wasn??™t much taller than her, his job had given Bart toned slabs of muscle, bulking out his shoulders, chest and arms. A trail of suds inched down Bart??™s four-pack abs, and Lisa??™s eyes followed the trail down to his erection. If he ever got laid off from the construction site, Lisa was sure he could write his own ticket as a porn star.
His dick was not just thick, but long, and they??™d been fucking for weeks before Lisa??™s pussy became used to his size enough that she didn??™t feel bruised afterward. Bart not only stayed hard through her climax but he could get hard again soon after his own. On the one or two occasions they??™d had the house to themselves, Bart had literally fucked her all night. To put it bluntly, Bart was hung like a horse and had the stamina of a bull.
She??™d lost count of how many girls had told her how hot her brother was now, but Lisa thought they were all missing the point.
Bart wasn??™t a hottie ??“ he was a STUD.
Bart was made not to shelter the female of the species, but to pleasure and breed them. There was more than one reason Lisa was so scrupulous about birth control ??“ not only did she have an IUD, but she made Bart use condoms whenever possible.
Lisa had always considered herself the moral centre of the Simpson family; in many ways she still did. But she??™d never felt any guilt whatsoever, even while sitting in church, about fucking her brother. Between running the family and trying to secure her future, Lisa??™s stress levels were constantly off the charts. Before she and Bart had stumbled into their incredibly effective and pleasurable form of stress relief, she??™d been having frequent, vivid fantasies of killing half the people she met, simply for annoying her. Unlike most people, Lisa knew that between her high intelligence and Bart??™s natural cunning and instincts for criminal behaviour, they really COULD slaughter half of Springfield and get away with it. So really, this was the lesser of two evils.
It wasn??™t like the Simpsons had ever been a normal family, anyway.
Bart was soaping up his cock, now, casually stroking his hard length with slippery fingers, and he grinned lewdly at her. ???Ready for round two already, huh Leese????
Lisa realised with surprise that she was fondling her womanhood, the folds already slippery in anticipation of her brother??™s penetration. Then she grinned back, and beckoned him forward with her free hand.
???More than ready. C??™mon, stallion, you??™ve got a female who needs to be serviced.???
Bart snickered, and stepped forward to press his body flush against hers. Lisa lifted one slim leg to wrap around his hip, and Bart bent his knees just enough for entry. As he straightened, he pushed his hips against her pelvis, so once the full length of his cock was inside her, the pressure of their bodies kept pushing Lisa further up the wall. Once Bart was standing naturally, Lisa was several inches off the ground, supported only by her leg around his body and one arm loosely slung around his shoulders, leaving her completely impaled on his dick.
???God, Bart, it feels like I??™m being fucked by a flagpole or something,??? Lisa moaned.
???Like that famous history guy said,??? Bart snickered, ???I have not yet begun to fuck.???
With the noise of the water covering the sound of their bodies slapping together, Bart fucked his sister relentlessly, rocking his hips to send her body up the slick tiled wall, and letting gravity push her down onto his dick, ruthlessly spearing her again and again while barely pulling out of her, so deeply she could feel the tip of his cock against her cervix.
Lisa loved it, but the slow thorough rhythym wasn??™t giving her the frantic stimulation she needed.
???Bart, please,??? she begged, clenching her pussy down on him.
Lisa was right on the edge, and Bart knew she needed to come really hard, this time. There was one thing that always made her go off like a rocket… Bart grabbed another handful of liquid soap, and gently rubbed at Lisa??™s asshole, before easing his soapy fingers inside. Lisa bit the hard muscle of his shoulder to muffle a loud moan of pleasure as he finger-fucked her ass.
???Yeeess Bart, that??™s exactly what I need, make me come hard…???
Lisa loved being fucked in the ass, but Bart??™s dick was so big that the one time they??™d tried it, Lisa hadn??™t been able to sit down for more than a few minutes the next day. Instead, Bart had become skilled at using his fingers or the vibrator Lisa kept for when he wasn’t available and she needed orgasms.
Bart bent his head to suck on Lisa??™s tits, flicking his tongue over a rock-hard nipple, and Lisa covered her mouth with her hand as she moaned Bart??™s name. Somewhere during the glorious freefall of her orgasm, Bart let out a beastly grunt that nearly made her climax again, and filled her pussy to overflowing with his cum.
Once she was able to stand, Bart clutched his sister close, partly for support because he was now so relaxed that his whole body felt like cooked spaghetti. Lisa shifted her weight restlessly, lightly rubbing her body against his.
???Damn, Leese, you??™re still horny???? Bart asked in surprise.
Lisa nodded, almost sheepishly. ???Ralph Wiggum. Math. How tired are you from work? Can you sneak into my room tonight????
???Sure,??? Bart grinned. ???You know I??™m always up for another taste of your pussy. But seriously – it??™s gonna be warm enough this weekend that we can drive up into the hills and really go at it. Want me to invite Millhouse to come along????
???Definitely,??? Lisa grinned.
Millhouse was still as devoted to Bart and Lisa as he had been in their elementary school days, and when he??™d stumbled across Bart and Lisa having sex, he??™d simply accepted it just as he did all the other weird shit in Springfield.
He had figured out he was gay a few months after Homer died, but though his mom was cool with it, given Springfield??™s attitude towards gays he??™d decided against coming out publically before college. Marge thought it was charming that Lisa was dating her brother??™s best friend, and never wondered why Lisa and Millhouse??™s dates were always at the same time that Bart went out with the guys from work. In reality, Millhouse would drive Bart??™s bike to a nearby town to see his boyfriend, and Bart and Lisa would take Millhouse??™s car to an isolated road ??“ or a closed-down factory, or even the top floor of a parking garage ??“ and fuck in the backseat for several hours.
What Lisa loved best of all, and made her come like a freight train, was being fucked by a dick in her ass and a cock in her pussy at the same time. Millhouse??™s long crush on Lisa lingered just enough that she was the only girl he could keep his dick hard for ??“ as long as he only had to fuck her in the ass.
???Hey, this way Millhouse can bring some burgers,??? Bart shrugged.
Lisa giggled and slipped out of his arms. ???Better go, or my hair won??™t dry in time for dinner. See you there!???
Bart shamelessly ogled his sister??™s ass as she left, then started whistling as he finished cleaning up.