Summer sighed deeply, staring at her reflection in the mirror. She knew there was a good chance Morty might notice her—provided he could overlook the fact that the impressive cleavage she was flaunting belonged to his older sister.
Morty wasn't exactly subtle when it came to his preferences. His current girlfriend, Jessica, was a prime example. Summer had stumbled across her social media after Morty tagged her in a few posts. The feed was practically a shrine to Jessica's figure, but what really set it apart was the constant, almost worshipful commentary. After Jessica had ascended to her status as the Time God, people practically lined up to gush over her posts.
It wasn't just her curvy figure that got the attention—though that certainly didn't hurt. Jessica seemed to have embraced her divine status, presenting herself as this untouchable, ethereal beauty. Picture after picture showcased her in tight outfits, sometimes posing with glowing artifacts, other times holding court over a crowd of literal time travelers.
And then there was that post by the pool. Jessica reclined in a barely-there bikini, tugging suggestively at the string strap while her eyes glimmered with golden light. The caption read, "Even gods deserve a day off." It was enough to make Summer roll her eyes so hard she thought they might stick. And yet, deep down, a small, rebellious voice whispered, I could do that better.
Summer tilted her head, studying herself in the mirror. Was Jessica's rack bigger? Maybe. But Summer liked to think hers were more proportional, fitting her lean, toned body in a way that screamed confidence. Her bust wasn't just big—it was bold. They defied gravity, sitting high and firm on her chest like they were designed to draw attention, whether she wanted it or not.
For years, she hated that about them. They felt like a curse in high school, earning her lewd comments and gawking stares. But now? Now she was starting to see them differently. Sure, Jessica might have the literal power of a god on her side, but Summer knew her appeal could still hold its own.
She allowed herself a sly smile. Maybe, just maybe, her assets would catch the attention of one particular pair of eyes.
"Summer!" Beth's voice rang out, sharp and matter-of-fact, cutting through Summer's thoughts. "Morty's on his way back. Rick says to make yourself useful and set the table before he starts complaining again."
"Yeah, yeah, I'm coming!" Summer called back, rolling her eyes.
With one last look at her reflection, Summer couldn't help but smile—tentative at first, then broader, as her confidence grew. Whatever she had felt about her body before, those feelings didn't matter now. All that mattered was that Morty would notice.
She grabbed a light cardigan, knowing she'd "forget" to button it up, and headed downstairs, her heart pounding with a mix of nerves and anticipation.
She looked amazing. When she complained about them to Mom for the first time since that summer day, she felt really good about her suddenly developed endowments. Though she had been a hot and sexy chick before, now it was a whole different ballgame. She practically oozed raw sexuality, bolstered by this newfound confidence, as she held her head high and thrust her bountiful chest forward. She would be dropping jaws and melting hearts and -- yes, why not? -- hardening cocks of every guy who lays his lecherous eyes on her sensational figure.
After years of adventuring with Rick, Morty wasn't the same timid, awkward boy Summer remembered from their younger days. He had grown into himself, shaped by interdimensional chaos and near-death experiences. His demeanor had shifted too. The nervous stammer that used to punctuate every other sentence was mostly gone, replaced by a measured calm and the occasional sharp wit. He wasn't afraid to speak his mind, even when Rick loomed over him, barking orders or spouting his trademark cynicism. And then there were his looks. Morty had grown undeniably handsome—a strong jawline, warm hazel eyes, an easy, crooked smile, and his monstrous boner he had watching interdimensional porn the other day made Summer's stomach flutter in ways she didn't want to admit.
Summer adjusted her olive-green cashmere sweater, the soft fabric clinging to her in all the right ways, before heading downstairs. The faint murmur of conversation reached her ears, Morty's voice rising above the rest. It was deeper than she remembered, smooth with a self-assured edge that sent a shiver down her spine.
"There you are," Beth greeted her warmly, looking up from the kitchen counter. "Come say hi to your brother!"
Morty stood by the doorway, his carry-on slung over one shoulder, chatting casually with Beth. His face, sharper and more defined than the last time she'd seen him, lit up with a dazzling smile as he turned toward her. Summer's breath hitched. He had grown taller, and broader, his denim blazer straining slightly over his chest and shoulders. Even with his clothes creased from the trip, he radiated an effortless charm that caught her off guard.
"Hey, Summer," he said, his voice low and sonorous. "Good to see you again. How've you been?"
"Not bad," she replied, keeping her tone casual even as her heart raced. "How was the trip?"
"Not terrible," Morty said with a smirk, shrugging off his jacket. "Plane food still sucks, though. Oh, and I could really use a shower."
Rick snorted. "Go ahead, enjoy your shower, your room, your—whatever. Just don't expect me to share any of the schnapps."
"Rick," Morty replied dryly, shaking his head as Rick sauntered off, muttering something about interdimensional gingerbread.
For a fleeting moment, his eyes drifted downward, and Summer stiffened. The glance was quick, but it lingered just long enough for her to notice. His gaze snapped back up, and he offered another easy smile, but her mind was already racing. Was it just surprised at how much she'd changed? Or had Morty noticed something... more?
"Yeah, you do kinda reek," she teased, stepping forward to wrap her arms around him. His embrace was warm and firm, and as she leaned in, her chest brushed against him ever so slightly. She couldn't help but wonder if he noticed—or cared.
"Summer, would you mind showing Morty to his room?" Beth interrupted, pulling a tray of ginger cake from the oven. "And maybe help him settle in?"
"Sure, Mom," Summer said, grateful for the excuse to steal a moment alone with him.
"Nah, I've got it," Morty said, hefting his larger bags. "But here, take this." He handed her his backpack with a lopsided grin. "It's lighter than it looks."
As they made their way down the hall, Rick's voice drifted after them from the living room. "Don't do anything I wouldn't do—or would do. Just, you know, keep it semi-legal!"
"Shut up, Rick!" both siblings called back in unison, rolling their eyes.
As she led him toward the guest room, Summer couldn't shake the sensation of his gaze lingering on her, even if only for a second. Her mind buzzed with questions, doubts, and an undeniable thrill she couldn't quite explain—or ignore.
So, aren't you missing too much school?" she asked as they reached the hallway. "Broke a few hearts this year already?"
She didn't entirely know why she asked that. Morty had been dating Jessica for over a year now, and she knew that. Maybe the strange, simmering feelings she'd been wrestling with lately had loosened her usual filters. The moment the words left her mouth, she regretted them.
Morty didn't snap back with an annoyed "What the hell, Summer?" as she half-expected. Instead, he let out a heavy sigh, his expression softening into something she couldn't quite place.
"Not really," he said, shaking his head as he set one of his bags down by the door to his old room.
Summer blinked, turning to face him more fully. "What? No hearts to break? That's not like you."
Morty chuckled, though it sounded more tired than amused. "Yeah, well, people change, Summer. Jessica's great and all, but it's not like I've been... whatever people think I've been doing out there with Rick."
Summer tilted her head, surprised by his tone. "So, what's it been like, then?"
Morty hesitated, his hand resting on the doorknob. "Complicated," he admitted finally, his eyes meeting hers for a brief moment before flickering away.
The atmosphere shifted, and for a fleeting second, Summer felt like they weren't just siblings catching up. She shook the thought away, plastering on a smile.
"Well, welcome back to boring Earth, then," she said, trying to lighten the mood.
Morty snorted, pushing open the door. "Yeah, boring Earth. Lucky me."
As he stepped into his room, Summer lingered in the hallway, her heart beating just a little faster than it should. Something about Morty felt... different now, and it left her both curious and unsettled.
"I wish," Morty said sardonically, hefting the bag onto his shoulder, "or maybe I wish I didn't have to try again... Not that I'm in any mood for that kind of thing right now, to be honest. But wait, how do you even know about this? We only broke up, like, a week ago."
Summer stopped mid-step and turned to him, her brow furrowed. "Wait, what? What are you talking about?"
"Me and Jessica. We broke up," Morty replied, his voice a mix of exhaustion and irritation. "Well, I broke up with her, but it's not like I had much of a choice..."
"What?!" Summer exclaimed, her eyes widening. "How did that happen? Did she—" she lowered her voice conspiratorially, "cheat on you or something?"
Morty let out a bitter laugh. "Not technically, but it might as well be the same thing." He shifted the weight of his bag and shook his head. "I found out she started her own religion."
Summer blinked, unsure if she'd heard him correctly. "What?!"
"Yeah," Morty said, his tone dripping with disbelief. "A religion, Summer. And not just any religion—a cult where she's literally worshipped as the supreme goddess of time or whatever. Apparently, she's been running it this whole time, like, behind my back. For months. And I had no clue!"
Summer stared at him, her mouth agape. "You're kidding me."
"I wish I was," Morty muttered, rubbing the back of his neck. "The worst part? It's not even the idea of the cult that bothers me the most. Like, sure, it's weird, but I've been through way worse with Rick. If she'd just told me at some point, I might've been okay with it. Maybe I'd even have been cool about it, you know? But she didn't. She lied. The whole time we were together."
Summer frowned, unsure what to say. "That's... a lot to process. I mean, a time cult? Seriously?"
Morty nodded, letting out another frustrated sigh. "Yeah. And the fact that she's so good at it... I mean, it's not just some dinky backyard thing. She's got followers. A lot of them. And they're devoted. Like, scary devoted. It's nuts."
Summer hesitated for a moment before placing a hand on his shoulder. "Morty, that sucks. I'm sorry. I guess it's a good thing you found out now instead of... I don't know when you're being dragged into some cult sacrifice or something."
Morty snorted, a small smile breaking through his frustration. "Yeah, I guess. Still sucks, though."
"Yeah," Summer agreed. "But hey, you're back home now. No crazy time cults here. Just boring, regular family dysfunction."
"Thanks, Summer," Morty said, his smile widening just a bit.
They continued walking down the hall, and for a moment, the atmosphere felt just a little lighter.
They came to Morty's old bedroom. It was still largely untouched, after he'd gone to college more than two years ago, and the sight of his private space was very welcome for the weary young man. He set the bags next to the wardrobe and sat down on his old bed, smiling wryly as he felt the familiar bounce of the well-worn springs.
"So, uh... what kinda stuff did she do, exactly?" Summer asked, crossing her arms as she leaned against the doorframe.
Morty chuckled, shaking his head. "Am I even allowed to talk about this kind of thing with my sister?"
"Hey!" Summer protested, flashing him a teasing grin. "I'm not some naive kid anymore, Morty. I'm an adult, remember? I can handle it. So spill."
Morty smirked, raising an eyebrow. "Oh, I've noticed you're not so little anymore," he said with a sly tone, making Summer roll her eyes. "Alright, fine. Since you're so curious… No, she didn't actually, like, have sex in her rituals as the supreme goddess, if that's what you're asking. Not with a guy or a girl. But what she did do was… uh… she streamed herself. Like, naked."
"Streaming naked?" Summer blinked, tilting her head in confusion.
"Yeah," Morty clarified, making a vague motion with his hands. "And she'd, uh, you know… get herself off. On camera. For her followers."
Summer's eyes widened. "Wait, what?! And you'd be okay with that?"
Morty shrugged, sitting on the edge of his bed. "Maybe? I mean, at first, it sounds messed up, right? Like, random dudes on the internet jerking it to my girlfriend? But… on the other hand… I don't know. It's kinda hot? As long as I'm the only guy who's, you know, actually with her, maybe it wouldn't be so bad."
Summer stared at him for a moment, processing the strange blend of his casual honesty and the bizarre situation. She set his backpack down with the rest of his luggage and walked over to the bed, plopping down next to him.
For a few seconds, she was quiet, her fingers tracing idle patterns on the fabric of the bedspread. Then she let out one of her trademark loud sighs, the kind she always did when she was trying to wrap her head around something complicated.
"Man," she finally said, glancing at him with a bemused smirk, "only you, Morty. Only you could end up in a breakup over something this insane."
Morty laughed dryly, rubbing the back of his neck. "Yeah, tell me about it."
"Masturbation is fine then," she suddenly declared, eliciting a chuckle from her surprised brother.
"Yeah, I suppose so," he admitted. "Though strictly speaking, this wasn't all that Jessica has been doing..."
"Oh? What else then?"
Morty looked at his sister, who regarded him with a playful smirk. His eyebrows rose, for he was more and more amused by Summer's unusual curiosity. At the same time, he thought there was no harm in indulging it. She was an adult and could discuss adult topics; for all he knew, she could've been sexually active herself.
"Well, you may or may not be aware that Jessica has rather, uhm, significant assets," he said, grinning in an uncharacteristically juvenile manner. "She's been playing them to her advantage. And by that,t I mean showing them, touching, sliding some, uh, toys between them -- things like that." He chuckled again. "Gee, I can't believe I'm talking about this with you! Not quite what I expected, coming home for Christmas. Why are you so interested anyway, in my ex who is now a goddess and her whoring out online for her cult followers?"
Summer leaned back on the bed, deep in thought. "Yeah, I mean... people can do what they want, right? I guess I just don't get why you're so weirded out by it."
"I don't know," Morty muttered, running his hand through his hair. "I guess it's just... hard to wrap my head around the whole thing. She was my girlfriend, and now she's some goddess of the internet or something." He shrugged again, trying to laugh it off. "It just doesn't seem real, you know?"
She bit her lip and held it, waiting for a surge of confidence that'd allow her to finally address the elephant in the room -- or two of them, more precisely.
"Uh, you know," she hesitated a bit, "maybe I'm feeling a bit of solidarity with your ex-girlfriend, as someone who's also in possession of the same kind of assets?"
Eyes widening, Morty cast a glance at his sister's clearly enlarged chest. Unlike the first time he did that when he thought it was probably just a trick of the light, he now allowed himself to really look at the intriguing shape of her breasts. They were definitely bigger than he remembered (not that he'd pay much attention to his sister's boobs!), and they were indeed very reminiscent of his ex's impressive bosom.
"Ugh, yeah," he had some words stuck in his throat. "I meant to ask you, but it felt a bit weird to bring this up..."
A wide smile curled the blonde's lips. "It's okay, bro. I know they are kinda hard to ignore," she said with a giggle. "Mom called it a late growth spurt. But whatever it is, it seems like it made me go up quite a few cup sizes."
There was little change in Morty's puzzled expression, even as he blinked several times. "You mean they are all natu--" he began, but then cleared his throat and said, "Uhm, I mean, yeah, you sure did, and you're right that they definitely stand out. Man, I hope you're not getting too much-unwanted attention because of them..."
"Oh? Nah, I'm not," she lied. "I wouldn't mind, though," she lied again, "since right now I'm basically in the same boat as you when it comes to, uh, dating and stuff like that..."
She leaned back on the bed, supporting her weight on the outstretched hands behind her. In this position, the girl's shoulders would naturally retract and her spine would arch slightly. The result was that she was practically thrusting her substantial breasts forward, making them spill and wobble with every idle sway, all while maintaining the pretense of a completely innocent, relaxed pose.
"Can't believe my brilliant, totally-not-lame sister can't find a date," Morty said with a sly grin, leaning back on the couch. "Although, as your brother, I guess I should be thankful that I don't have to scare off any guys... especially with Rick around, you know? He'd probably kill them in their sleep and dump the bodies in a vat of acid or something."
Summer laughed, rolling her eyes. "Oh, don't worry, Morty. My virtue is just fine, thank you very much," she teased. "And I'm pretty sure it'll stay that way until college. Unless, of course, I decide to follow in Jessica's footsteps and become a 'content creator' myself..."
Morty's eyes widened in horror. "You wouldn't!" he gasped, a mix of shock and disbelief on his face.
"Why not?" Summer shot back with an impish grin. "I've got the right assets for it, don't you think?" She smirked, folding her arms confidently as she looked her brother up and down.
Morty quickly turned away, face red, mumbling, "I-I mean, that's... uh, that's not the point, Summer! You could... I mean, ugh, please don't!"
She made her point even more abundantly clear when she shook her shoulders, causing the entire delightful mass of luscious tit-flesh to bounce and jiggle enticingly. Try as he might, Morty couldn't help but watch them move under her thin sweater, captivated by their playful, almost whimsical dance. He also caught glimpses of what looked like an unusually decorative bra, frilly enough to crease the cashmere wool that stretched taut over the large expanse of his sister's bosom.
"Sheesh, Summer," Morty groaned, rubbing his temples. "How am I supposed to answer that?"
"Honestly, of course," Summer teased, crossing her arms with a sly grin. "Like the qualified expert you are, Morty! Come on, give me the lowdown!" She winked before adding, "But alright, I guess I can let you off the hook for now. Go take that shower, alright?"
"Yeah, I think I need it more than ever now," Morty muttered, shaking his head and forcing a dry, amused smile. "Alright, fine. Anyway, if you run into Dad, tell him I'll help with the lights outside in like, fifteen? Okay, maybe twenty minutes."
"Sure thing," Summer replied, watching Morty grab a change of clothes from his bag. Once he shuffled off to the bathroom — which, of course, connected both of their rooms — she got up and headed out of his room.
In the hallway, as the door behind her closed, she put her back against the wall and closed her eyes. She took a deep breath, followed by another, and after a couple more she finally let out a relieved sigh.
Her heart was racing but she continued to keep her cool -- or most of it anyway because she couldn't fight the wide, goofy grin that dug deep into her high cheeks. She chuckled, amused at what transpired between her and Morty just now. She was overcome by a heady sense of a hitherto unknown power, one which she had invoked very successfully without paying it so much as a thought.
In other words, it worked. Morty was absolutely noticing her, and how! When she did that little shake, his eyes were practically glued to the luscious, jiggling expanse of her stunningly large rack.
Once again, it made her smile. Why wouldn't it? Her hunky older brother, whom she'd been crushing on since last summer, was clearly responding to the feminine charms of his bosomy sister.
"Welcome home, bro," Summer whispered, as she bounced off of the wall and strolled happily down the hallway.
***
He said twenty minutes. He thought that would be plenty of time, to take a shower and put on some fresh clothes. All he wanted was to wash off the discomfort of fitting his tall frame into a tiny window seat with a view of the flyover country.
Normally it would have been enough time, but the weird exchange he'd just had with Summer had made it anything but normal.
"Fuck!" he cursed under his breath, banishing yet another unbidden thought from his mind. "No, not her! Jessica, dammit!"
With one hand on the tiles, he slouched under the biting streams of water. His other hand had been much busier, traveling up and down the entire length of his full, angrily throbbing erection. It did stop now, however, as Morty battled the wholly inappropriate image that kept popping in his head, over and over again. He tried to dismiss it, to think back to his stacked ex-girlfriend and those big knockers she'd sometimes wrap around his large hard-on; or even to the many lewd videos she had made, which he did watch in a moment of weakness and enjoyed more than he would like to admit.
Now he was picturing her again, large plump ass high in the air as he pounded her slutty cunt for what little she was worth. Hands on her hips, digging into the soft flesh, he thrust deep into her wet pussy and felt his balls slap her thick thighs, every time he bottomed out inside her hot tunnel. She was on all fours, bracing herself against the force of his rapid plunges; but she could not steady the rocking and the swaying of the big pendulous boobs that hung below her torso. Every time his cock reached her cervix, these massive globes would shake from the impact, hard pointy nipples drawing his attention as they begged to be squeezed and pinched.
"Fuck me, Morty! Fuck me!" urged Jessica in his fantasy, moaning in unbridled pleasure. "Oh yes... YEEEEES!"
She howled and shuddered from a powerful orgasm, inflicted upon her voluptuous body by his thick, rock-hard manhood. He relished the ease with which he could bring the curvaceous redhead to a screaming climax, if only in his fantasies, as he stroked his rigid shaft and imagined it was the warm wetness of Jessica's tight pussy that enveloped every solid inch of his dick.
He groaned and kept on masturbating, a smile crooking his half-open mouth. The vision in his mind started getting hazy, distorted by the upswell of surging, primal lust. Gradually it became less and less detailed, as it narrowed down to the bare essentials only -- raw, carnal, and pure.
"Yeah, that's good," he muttered. "You're liking it, huh?... Cum again, you slut!"
She did, obviously, her mental image obeying Morty's commands instantly and without question. He was close now, jacking his hard cock at an increasingly frantic pace, as the water cascading down his sculpted body slowly started to turn chilly.
"Oh yes... Almost there..."
Finally, building pressure at the base of his turgid rod came to a boiling point. His imaginary lover, now little more than a sensation and an indistinct picture of a curvaceous goddess, shrieked in one final orgasm. But rather than disperse into nothingness, or at least slump onto a nonexistent bed and present herself as the target for his impending eruption, she did something completely unexpected.
She turned around and smiled. But not like Jessica would, no.
It was Summer's smile.
His sister was looking at him. Grinning from ear to ear. Expecting him to unleash a torrent of brotherly cum to fill her well-fucked, yet very hungry pussy.
"What the --" he croaked, just as the first salvo jetted out of his spasming cock. "Summer! Oh fuck! Oh god..."
More and more spurts came, each one making a splash on the tiled wall before washing away and disappearing down the shower drain. More and more shots rocketed from his rampant dick, each one recoiling with spine-tingling pleasure that overwhelmed every other feeling. More and more volleys, heavy with his potent seed, each one aimed at the sultry, teasing, very mischievous face of his hot, busty sister.
"Fuck, fuck... Ahhh! Summer..." He kept jacking, and he kept cumming. "Arrgh! Fuck it! Take it all, then! Feel your pussy... being filled... with your brother's cum!"
With a few more twitches and a final straining groan, this momentous orgasm finally drew to a close. He panted hard, holding his reluctantly softening dick, struggling to stand as the massive eruption sapped his strength and racked him with a sudden pang of guilt. The water was practically cold now; a violent shiver coursed through his body. He shut it off and put both hands on the wall, breathing heavily, trying to untangle the jumbled mess of shame and lingering arousal that weighed upon his broad shoulders.
Meanwhile, his sister was still looking at him. Still smiling. But it wasn't just the seductive visage of Summer in his mind.
---
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