Yeon-woo's First Sex Slave Service

Cheol-gyu Lee thought there was something strangely intriguing about the cousin-sister relationship. It wasn't as close as a real sister, yet not as distant as a stranger either. Family, but not quite. An ambiguous position. That's why, from way back, he'd jerk off to his cousin-sister Yeon-woo Lee as his fantasy girl—guilt lighter than with a blood sister, but the intense taboo thrill because she wasn't just some random girl.

"Haa... haa... haa..."

So when he shoved the camera right in his cousin-sister's face and barked at her to sign the sex slave obedience contract, it hit the same spot: less guilt than a real sister, but that raw, forbidden rush since she wasn't unrelated. And she wasn't just any cousin-sister—this one was excessively sexy, excessively (at least to him) arrogant. Reducing that haughty, stuck-up cousin-sister to his obedient sex slave, step by step, gripping her weaknesses... the pleasure of this moment overflowed with a twisted conquest like ancient tribes enslaving enemy villagers after victory, or pirates cackling as they raided towns and massacred people. Immoral for sure, but the dark pleasure humans have chased through history.

And Yeon-woo Lee, the victim of that dark thrill, stood under crushing pressure that made her vision swim and nausea rise.

"What? Can't do it?"

"...B-but..."

"Don't wanna? Fine, then I'll blast the videos everywhere, go to jail myself, and everyone finds out you're a whore—Uncle and Jin-woo Lee too. First offense, Dad's rich, so probation at worst."

"...."

"You can't, right? Wanna try? Send Jin-woo the link first? Yeah? The fresh video and pics I just edited, all of it..."

"....N-no, don't...!"

It was just scrap paper with no legal weight, pure coercion—but if she 'admitted' it herself... she instinctively knew her life would change forever.

So she bit her lip until it bled, hands trembling as she agonized. But in the end, she had no choice but to bring those shaking hands to the contract. She was the one with everything to lose.

Swallowing vomit, eyes unsteady, she reread the contract she'd already scanned, denying reality, then asked in a quivering voice.

"Wh-what's ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠the... daily mission...?"

"What else? Never read any smut or hentai? Oh, right, you wouldn't. Girls like you are too cool for that."

"...."

"You gotta do the missions I assign each day. Nothing too crazy. I'll keep it at the level you already post on Sextwitter. Like, masturbate here and upload it~ that kinda thing?"

"....S-so I have to obey those...?"

"Fuck, can't you read? King's gonna cry."

"...."

"Hey, hey, lighten up. Can't ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠even joke. Anyway, I'm not backing you into a total corner, right? It's there in black and white—if you can't do the mission that day... just take 'punishment' from me."

Yeon-woo stared blankly as Cheol-gyu Lee leered and blabbed.

"....Punishment?"

"Don't know what that is? I get to slap your cheeks, tits, ass, choke you—whatever."

"N-no, that's..."

"Might be good for you? You're a maso bitch who loves getting hit, right? Yesterday you went full ahegao when I choked you—fucking epic."

"...Where the hell did you even hear that...?"

She almost snapped her usual "Where'd a weeb loser like you learn that crap?" but flinched, checking Cheol-gyu's eyes. He wasn't just some harmless otaku loser anymore... he held her leash.

Sure, still a weeb loser—but one gripping her social life. No, that made him more dangerous. Zero real dating experience, just endless porn, smut, hentai fueling brain fantasies... now armed with that warped, third-rate hentai logic, eager to toy with her for real.

Like how kids are deadlier to dragonflies than adults. Staring into Cheol-gyu's cold gaze, Yeon-woo felt like that helpless insect facing a cruel child.

In the end, after a few timid protests, she had no choice but to stamp it. Her fingerprint.

====

'Haa... haa... is this for real? Wow... it's happening.'

Funny—or not for Yeon-woo—but Cheol-gyu too stared down at his cousin-sister inking the 'sex slave contract' he'd scribbled on a whim, heart pounding wildly inside.

Because... honestly, no master plan. No thought to consequences. Pure impulse.

Even while threatening, his rational brain screamed 'This real? Gonna fuck my life up? Jail? But I want it so bad fuck it'—reason vs. lust duking it out. Lust winning thanks to the rush of humiliating his arrogant cousin-sister.

To her panicked eyes, he seemed a cold monster. But really, he wondered if this blackmail material would even stick—or if it'd backfire and land him in prison. Reality's a bitch.

But... in the end... watching her stamp that absurd contract eased his anxiety. Somewhat. Still just worthless paper, but her own voluntary act crossed a mental barrier.

At least now, within limits, she'd submit to his 'obedience' and sexual exploitation—by her own agreement.

Emboldened by her submission, Cheol-gyu grabbed her hair violently, dropping the formal talk for raw aggression.

"Haa... fucking bitch, took forever. Listen up—from now on, drag like this and you're dead. Got it?"

"...Y-yeah, got it..."

"Got it?"

"...G-got... it..."

Already, this bogus contract psychologically bound Yeon-woo's actions. We agreed, right? So she submitted out of fear, and he could unleash violent urges without restraint.

Cheol-gyu had his swollen, throbbing cock out for over ten minutes already. He pulled it from his zipper and thwack! thwack! slapped his cousin-sister's pretty face with that meat club.

The humiliation of a man's dick stinging her face. She winced, eyes shut, enduring the shame—but couldn't block the thick precum from his unwashed glans splattering her cheeks with wet splats.

Swallowing the rising humiliation like vomit, she bowed her head...

"Hey. Lick it with your tongue."

"...Y-yes, M-Master."

She had to accept the cold command from her maso slave mindset. Kneeling on her own, she started lapping and sucking Cheol-gyu's massive banana cock with devoted care.

=====

She'd already taken 200,000 won like a sucker for a few oral sessions before, but context mattered—dark corner or not, this was the academy storeroom. A public space where anyone could walk in anytime. Forcing his cousin-sister to suck him off here? Way hotter than regular blowjobs.

"Haa... haa... fuck, that's good..."

His defeated cousin-sister knelt between his legs like a dog. Her small head bobbed busily up and down; below, her dizzyingly slim waist, round massive ass thrust back, pink heels neatly together—all in view at a glance. A sight to make most guys blow instantly.

And slurp... smack... slurp—her pro skills from sucking countless cocks, flawless. Visual and tactile overload.

But Cheol-gyu, 19 years of zero real sex, just fantasies? Not enough. He craved darker, more depraved stimulation than average ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠teens.

"Ngh... good... our sis sucks dick like a pro. Real whore material."

His words sliced like a knife, mocking her. He shoved the phone camera at her beautiful face slurping his cock so vulgarly.

"Look here while you suck."

"W-wait, my face...?"

"I know. That's why angle it so your face shows. Suck."

"Th-that's...!"

Filming. She hesitated—too much—but

By principle, she had to do any act he wanted. Disobey? Slap!

First slap from a man in her life. Burning heat crept over her cheek; Yeon-woo looked up at him with disbelieving, fearful eyes.

Never even hit by Dad...? The raw pain drilled home her physical weakness.

"Not paying attention? Starting without 'Master'? Huh?"

"...S-sorry, Master..."

Unfamiliar submission. Unfamiliar pain. She bowed her head quick, apologizing humiliatingly—but Cheol-gyu didn't forgive generously. Another demand.

"Hey. Skirt off too."

"...Yes."

Hesitant, she slid down her skirt—panties already gone, bare pussy exposed.

"Nice. Body's built to fuck."

"..."

"Just sucking's boring, right? Here, take this."

"...Huh?"

He held out a thick oil-based marker.

"I'll ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠doodle on you every time you disobey. Keep it on for OP tonight—show the clients. Soft punishment, yeah?"