Crossing the boundaries

Mark released a moan as Kelsey's mouth gently enveloped his cock. Her tongue licked its head as the busty blonde moved with uncertainty. She looked up at her brother lovingly. He didn't need to tell her what to do; she almost immediately began pushing it deeper, inch after inch. The movement was clumsy, but it felt heavenly.

"Oh fuck, Kelsey," he gasped, feeling his sister's tight mouth slide down his length before she slowly ascended and repeated. He caressed her cheek with one hand before his other pushed down her mane of blonde hair. "You're a natural at this."

The young woman suddenly sped up, encouraged by his compliment. As she **** herself down, she made a quiet **** sound and bolted up her brother's shaft. However, contrary to what Mark expected, she never let him exit, her lips tightly locked around the head, her tongue continuously working him as she calmed down. He could tell that with every second, she got more into the act. One of her hands snaked down her stomach, teasing her pussy through her panties, while the other fondled her breasts tenderly.

The movements continued for nearly a minute more. Mark felt Kelsey quickly pick up on all her sweet spots, making sure to stimulate them extra hard.

'There's no way this is her first time...' the thought rang in his head as his orgasm approached. He'd been blown by his girlfriends before, and Kelsey left them far in the back. Either she was a natural cock sucker or she had trained on something, he figured.

That thought was suddenly interrupted when he felt his floodgates open.

"Fuck, Kelsey, I'm coming!" he announced. With a raspy gasp, he grabbed Kelsey's head, slamming her down to his pelvis.

The buxom blonde made a gargling sound as she felt his cock pulse in her mouth.

Then came the sweet release.

Mark's cum painted his sister's throat in several powerful shots. Kelsey choked, her body instinctively tensing up at the hot invasion down her esophagus. The sheer amount of the baby batter was too much for her to handle at once, some of the white cream reaching the rims of her mouth and escaping there. Her eyes went teary, slight streaks running down her cheeks and messing up the thin layer of makeup on her skin. Yet, she didn't back off. Eyes still affectionately focused on her brother, Kelsey took the entire **** of his orgasm head-on.

As his release subsided, Mark released his hold on his sister's head. The blonde woman ascended with a sluggish motion, her gaze dreamy. A loud gulp sounded as she finally had the chance to swallow, but not without slight amounts of cum trickling down the corners of her lips. Yet, she appeared not to care.

Opening her mouth wide, Kelsey fixed the helmet of Mark's cock on her tongue, playing with it idly as it still twitched, final spurts of cum painting it as she panted gently.

"Oh fuck," the black-haired man huffed, still coming down from the high of pleasure. There was no denying; this was the most powerful orgasm of his life, released straight into his little sister. The taboo nature of the act sent a pang of even stronger pleasure down his spine, making his cock throb with newfound hardness. "That was amazing, Kelsey," he said, looking down at her.

She beamed, her mouth curving into the widest smile he'd ever seen on her. Her beautiful eyes were unwaveringly focused on him, and Mark could've sworn he saw hearts appear within, but he dismissed the notion.

"Thank you, big brother," she replied. Finally popping his cock out of her mouth completely, she gave its slit a big, loving smooch. "I love you."

"I love you too."

His attention was then drawn to Kelsey's body as a whole, quickly noticing that all this time, the busty blonde was idly playing with herself, even during their exchange.

She picked up on his gaze. Her movements froze for but a blink, a strong flush gracing her face.

"Want to go further?" he asked.

Kelsey almost shook, visible conflict surging from within. Her expression turned stunned, then slightly elated as she nodded faintly.

Mark didn't wait around.

"Lay down on the bed, Kelsey," he commanded her shortly. "Your brother wants to reward you."

Her expression turned ecstatic yet expectant as she wordlessly complied. As she passed by him, Kelsey made sure to wiggle her bubble butt. Her heavy breasts swung with every motion she made, eventually setting as she turned on her back.

Kelsey was nervous. Mark could easily notice the way her body twitched as he stared at her, wolfish hunger underlying the need they both felt. Clad in her underwear yet naked in front of him, he could imagine how she felt. Wrong but right. Right but wrong. Enticed but guilty, and much more.

But he wasn't going to let the dichotomy last.

He reached out to Kelsey's rear. Sinking his hand in the abundant asscheeks, he let out a lowly chuckle.

"You're hot as fuck, little sister," he commented, ascending above her. As she lay before him, he was hunched just above her, the difference in their heights now more prominent than ever. Her diminutive five foot three felt almost nonexistent next to his six foot four stature.

"Mmmm, big brother~," Kelsey moaned at the compliment, her thighs rubbing as she put both hands on her tits. For long seconds, she kneaded them through her bra before she felt her brother reach out to help her. "Play with them~," she gasped huskily between breaths.

Mark's cock pulsed, hard enough to drill into concrete at this point.

With a firm tug, he released Kelsey's big breasts from their confines. Their perkiness kept them from sagging much, her small, pink nipples sitting atop puffy areolas and pointing into the ceiling.

Kelsey shuddered as he clasped his hands around them with ****, lightly squeezing her nipples between his fingers.

But Mark had more in his mind. Slowly, he relented his hold, letting Kelsey continue teasing her pink mounts by herself as his hands descended her frame, slowly and tenderly tracing her delicate skin. In between her moans escaped a few small giggles as she felt the ticklish sensations of the touch.

Mark's face was inches away from hers. Slowly, he nudged his nose against her cheek, kissing her tenderly before moving slightly down.

"Oh, big brother," Kelsey gasped heavily as he licked her neck, and then found his way to her breasts. "Yes, kiss them~."

And he obeyed. Planting a wet, sloppy kiss on his sister's nipple, Mark felt her quake under his hold like she just had a mini orgasm. He repeated the action on the other one, earning himself a moan of approval before he descended further.

Kelsey's underboob was next on his visit, showered in many tiny kisses. Then came the time for her navel. Then, he found his way to her panties. Black as they were, their positively drenched state was given away by the sweet scent of her juices.

"Ready?" he raised his head lightly. From between the prominent boobs she continuously played with, the blonde woman stared at him, untold lust within her blue eyes.

She gave him half a nod. Mark acted in an instant.

First came a light kiss. Kelsey let out a loud gasp as he pressed the material into her cunt. Then, he moved his hands, slowly grabbing the hem of her panties. With a teasingly deliberate motion, he undressed his sister completely, giving himself the view of her most sacred hole.

Kelsey's labia was swollen with arousal, glistening with her juices and pulsing with her rapid heartbeat. Bringing a finger closer, Mark teased her entrance briefly. Her legs twitched.

And then, he brought his face closer. He drank in her delicious scent, savoring it like the sweet nectar he was about to taste.

He began licking his sister's pussy.

"AH!" Kelsey let out a moan loud enough to be heard outside the room before she put a hand over her mouth.

Meanwhile, Mark licked, kissed, and explored Kelsey's cunt. He felt it spew hot juice onto his tongue, and he lapped up every last drop. He carefully studied her reactions, picking the spots with precision, and pushing her buttons one after the other. His sister's continuous spasms and forcefully stifled moans informed him just how well he was doing.

Suddenly, he felt her hand on his head. Shooting a glance upward, he could see Kelsey's face, redder than a beet, tears of joy streaking down her cheeks. A quick exchange of gazes was enough to tell him; she was close, and it wasn't going to be a small one.

He redoubled his efforts, the small hand in his dark hair pushing and pulling as though unsure if Kelsey wanted to come or ride the high of pleasure forever and ever. He pressed his tongue with more ****, scraping her labia with his mouth, and sucking at his little sister.

And then, he felt her convulse. It was different from her earlier reactions; way stronger, more primal.

Kelsey came with a shout she barely managed to stifle with a pillow. Her body shook intensely, her legs clenching around her brother's head. Her pussy exploded, a powerful squirt of her juices hitting Mark squarely in his face. The stream lasted a long moment, soaking his hair and the material under his chin.

And then came the moment of calm.

Mark slowly lifted himself, gently forcing Kelsey's legs apart as he stared at her.

She lay before him, only her bra just under her breasts still on her. Her entire body was flushed with arousal, slight pangs traveling just under her skin and making her muscles twitch unconsciously. A sheen of sweat made her skin glisten like a crystalline piece of art in the sun falling through the window. Her expression was unfocused, her tongue out of her mouth as she breathed heavier than he'd ever seen her before. The pillow she lay on had a large wet spot on its surface, right where she had screamed her soul out just now.

Mark wiped his face and slowly moved above his sister. She shuffled slightly, blinking once or twice before taking a deeper breath. Her eyes met his, focus slowly returning.

"I didn't know you were such a squirter," he said teasingly, unhurriedly descending and kissing her.

Kelsey gasped, her mouth forming a silly smile. "I didn't know, either..." her voice trailed off, her mind still partway elsewhere.

A few long seconds passed before Mark shuffled back. Drinking in the luscious image of his hot sister, he was almost immediately reminded of his cock, which throbbed furiously, pointing right at her.

Kelsey seemed to sense it, her unsure gaze flicking between the rigid tool and her brother's face. She didn't need any explaining to know what he wanted. Truth be told, deep in her, she also felt that way. This situation felt wrong. It was wrong, she knew it. She was raised to know it was wrong, for her to love her brother like this. But... why didn't it feel so? Why did Kelsey feel her lust only burn brighter at the thought of her brother taking her? In front of her eyes, she was already picturing it all. From this simple act, to becoming official, to her donning a white dress--

"Kelsey."

She was brought back from her mindscape with but a word. She met his gaze again. Her heart fluttered, her stomach overcome with butterflies.

"M-Mark," she stuttered, a pang of arousal making her body shudder.

Mark shuffled closer. His face inched toward hers. At the same time, she felt his cock gently lay above her pussy, rubbing against the small plume of pubic hair she sported.

Their lips met gently, the two still savoring the moment.

And then, he broke the tension.

"Do you want to go further?"

Kelsey's heart halted at the question. She knew what she should say. She knew what she had to say. But at the same time, she knew what she wanted.

"This is... so wrong," she said. "We shouldn't... but... I want it... big brother," Kelsey admitted, her eyes unwaveringly focused on her brother's. "I want it from nobody else but you. P-Please... love me."

Mark lowered his lips, kissing her again. Their hot breaths combined as they got into the act. As their saliva mixed and their tongues struggled, their bodies moved. Acting on instinct, the blonde woman spread her legs slightly as the dark-haired man pulled his hips back, one hand guiding his cock toward her entrance. The slickness of her labia welcomed him as his head gently parted the first fold.

"I will," Mark said as they dislodged. "I will always love you, little sister," he continued, caressing her face with care. "Ready?"

Kelsey's breath hitched in her chest at the way he said the sweet words. She gave him a weak nod, unable to express her eagerness anymore. She only wanted to feel it.

Encouraged by her confirmation, Mark fixed his position. And then, he gently pushed.

"AH!" Kelsey let out a loud sound as his first inches entered her. She was just barely able to hold it in with the help of her hand. Her breathing became erratic as she savored the pain and pleasure alike.

Mark halted, seeing her reaction. He could feel the immense tightness of his sister's unused pussy, wrapped around him like a hot glove that continuously massaged him.

He relented, exiting one inch, then another. But suddenly, he felt the blonde bombshell lock her legs behind his back.

"More..." she said quietly, her tone underscored by lust and affection. Though tears escaped her eyes, her gaze was unbroken. "Push it in more..." Kelsey pleaded, her whole body shuddering as Mark obeyed. "Yes--Mgh!" she almost squealed.

Mark looked down at the place where they connected. Four inches of his cock had disappeared into his little sister, but five more awaited, his entire shaft pulsing in a primal rhythm that begged him to push it all in. Looking back at the blonde girl, he could see that she wanted it. She wanted a closer connection.

And he wouldn't disappoint.

Kelsey's free hand clenched the duvet they lay on, pulling at the material as her brother's cock split her insides. Five inches. Six.

"Fuuuuck!" she cursed, just barely not shouting.

Seven.

"Nghh!" she convulsed, almost completely overwhelmed. It hurt. It hurt to push it in like this. But... for some reason, she loved how it felt. She loved it, knowing it was her beloved brother who did it. The wave of pleasure right after the pain was the sweetest thing she'd ever felt. And she wanted more.

Eight.

"Kelsey," Mark gasped, lowering his face to his. "Are you alright?" he asked, kissing her cheek lightly. "Should we slow down?"

"Fuck... this hurts... but it's so good..." she said dreamily. "Why does it... hurt so good...?" her blue eyes barely focused on him, a silly smile on her plush lips as she kissed him tenderly. "I want it all... big brother~" she purred, biting his lip. "Push it all in~."

Mark felt his heart flutter. His bombshell sister, a perfect combination of cute and sexy, looked at him with a more loving gaze than he'd ever remembered. The way she smiled told him she enjoyed the act.

Therefore, he didn't wait.

Relenting just a little bit, Mark took a short, steadying breath, before plunging in, sheathing himself completely in his sister.

Kelsey turned her head, releasing a profound shout of pleasure into the pillow. Her entire cunt squeezed on Mark's cock tightly, every inch massaging him with fervor. Her body shook and quivered, new drops of sweat appearing as her breathing slowly stabilized.

"It's all in... Oh God... it feels amazing..." she said absent-mindedly, still processing the situation fully.

"You're doing great, Kelsey. " he gently rubbed her cheek with a thumb. "I'll begin moving, alright?" he asked,

Kelsey immediately sought out her brother's hand, sucking on the finger almost on instinct. Looking up at him, she nodded. "Love me, big brother."

Mark backed off slightly, grabbing his sister's legs for stabilization. After he let Kelsey get used to the sensation, he gently pushed back in. And then, back out again. In and out again.

Her moans pierced the bedroom's stale air. With every motion in and out, Kelsey's pussy resisted the **** just a little bit less. The pain of the act faded into obscurity, replaced by the blissful pleasure. As it did, Mark started speeding up.

With every strong move, Kelsey's ass rippled, every tiniest bit of her rear feeling Mark's movements. Her taut tummy was not left untouched, slight waves traveling across its surface as well. Her big breasts jiggled enticingly with every move, the movement hypnotic. Kelsey's hands gripped them tenderly, the woman relishing in the feeling. She twisted her erect nipples gently, another spasm of pleasure rocking her in tandem with her brother's thrusts.

"Oh!" she gasped. "Big brother! I'm close, I'm close!" she chanted.

He barely answered. He could feel his own release coming in big steps.

Mark lunged at her. Their lips met, their wet embrace filled with lust transcending what they thought possible. His hips pushed into her even faster, her big bosoms moving between their chests, her areola and nipples brushing his pecks.

And then, Kelsey came. Hard.

Mark felt her tighten against him. She pulled him into her, her legs locking behind his back, her arms clutching him with strength he didn't think belonged in the small and fragile body of the voluptuous blonde in front of him. Her nails scraped his back. Her tongue fought his fiercely, a loud moan trapped between their lips as she shuddered, the **** of her explosive orgasm rocking her with ****. Her vagina clamped down on his shaft almost as if it wanted to break it. Her pussy squirted, splashing her juices against Mark's pubic area.

Mark's release came almost immediately afterward. His rigid shaft pulsed within Kelsey's insides, its tip right against her cervix as he released a guttural moan. Pushing as far as he could, he felt his balls tighten, churning and sending out a new load.

There was no time to pull out, nor was there any thought of doing so. Mark's cock began spraying the insides of his busty sister, painting her whole with his hot cum. One shot, two shots, and more, all released within Kelsey's begging cunt.

She kissed him with more fervor, feeling the searing hot sensation of the incestuous baby batter filling her. Her hips rocked weakly against him, almost as if enticing him to release one more shot, and one more again.

And then, the lengthy sensation of release slowly waned.

Kelsey's muscles weakened. Her hands unclutched from her brother's back, and her legs gave out the last of strength they had, limping down. Her lips disconnected from his as the man raised on his elbows. The thick strand of saliva between their mouths signified the timeless moment, solidifying the nature of their connection.

Slowly, Mark exited his sister's snatch, a trail of cum following. He lay down next to her, his muscles spent, before looking over her.

Kelsey breathed shallowly, slowly recovering from the earth-shattering **** of her own orgasm. She seemed to look at him, but the blue of her eyes was almost blank, her mind lost in the throes of pleasure. Sporadic spasms traveled through her, making her bubble butt and big breasts jiggle.

A whole minute passed. Kelsey slowly twitched, blinking lazily as her body started recuperating from what just happened.

Her hands lazily grazed her body, grasping her hips, then her breasts, before she wiped sweat and tears off her face. She let out a prolonged sound, something between a yawn and a moan before her hand met Mark's.

She stiffened, her gaze suddenly focusing on him. But then, the uncertainty melted. The blue of her orbs emanated docile affection as she slowly scooted closer. Her head rested near his shoulder, her legs twitching as they crossed his. She felt a trickle of cum escape her lower lips. She almost shuddered at the sensation. Her breath hitched as she inched ever closer.

"Big brother," she said softly. Her big breasts brushed against his shoulder as she slowly ascended. "That was..."

"...amazing," he finished, looking back at her with the same, affectionate gaze.

"Yeah..." Kelsey nodded.

A moment of silence passed. Mark's hand found its way to the watch nearby, clenching its chain subconsciously. How did his grandfather get this item...? Why did it work...? His mind was filled with uncertainties, which were only amplified when he glanced back at the buxom babe next to him. He could not believe what just happened. He was ready to accept he would wake up any moment, alone.

But that thought was swept from his mind when Kelsey's hand tightened around his.

"Mark," she said his name affectionately.

"Yeah, Kelsey?"

"Does this... make us... a c-couple?" the busty blonde asked, her voice a little hesitant.

Mark's heart skipped a beat. He remembered what he had told Kelsey during her trance. This escalation was a major step, even considering what just happened. The fact that she inquired about it meant that she had internalized the trance commands and rules. This meant one thing.

"Do you want us to be?" he rubbed her shoulder briefly, his hand then descending to her breasts. He clasped one perky orb in his hand, gently squeezing it and eliciting a gentle moan.

"I... yes, but..." Kelsey's gaze skittered. "This... this is wrong... everyone will look weird at us... I-I mean... mom is downstairs... how do we... even say it to her?" she asked, her gaze unsure.

"We don't have to say it now. We'll cross that bridge when we get to it," he replied, his tone now firmer, surer like a traveler who just found a new grand destination to reach. "For now, let's not worry about that, alright?"

Kelsey shrunk in his embrace. Her muscles relaxed against his, her eyes closing. Although her breathing had stabilized, Mark could tell she was tired.

"A-Alright..." she nodded, rubbing her cheek against his before planting a wet kiss on his cheek. "I love you, big brother."

His head turned, reciprocating with an equally moist kiss on her plush lips.

"I love you too, little sister."

A/N:

Well, firstly, allow me to say: thank you for reading!

Secondly: just a little over 7k words. Huh.

I did not expect it'd stretch like this in just 2 chapters. I had more planned (including getting Mark's mother in on the action) but oh well, 7.5k marks the limit, I won't be nagging about it. Count your blessings, I tell myself. I might extend it if it's requested (or just out of boredom when doing other things, we shall see).

On that note, I hope everyone enjoyed this little piece. It was a nice break from the things I usually write.

Again, thank you. To everyone, I bow my head.

This has been MH-0 'MeedrowH'. Thank you for reading, and have a wonderful time!