A Sister's Shadow

"Aren't you sorry toward your sister?"

"Uh… how… stop that…"

Her voice trembled violently at the thought that her shameful state had been discovered.

Her face flushed crimson in an instant, and her flustered eyes darted quickly toward the kitchen.

[Target: Kim Eun-su, Emotion Level: 36]

The sound of Eun-jung washing dishes, water running, and plates clinking echoed clearly.

Each sound struck her heart like a hammer.

Tae-seok's hands began touching her body more blatantly.

"You were thinking about me while doing it?"

"No. What are you even thinking right now? I've never done that."

She denied it even faster this time.

"Auntie, your lies are way too obvious."

"If you keep messing around… I'm going to get angry."

"Go ahead and get angry. I'd love to see what you look like when you're mad."

Tae-seok grabbed her breasts and kneaded them roughly.

"Haang~ Seriously, what's wrong with you? My sister… she'll be here any second…"

Kim Eun-su barely managed to speak in a trembling voice.

Those words were neither permission nor refusal.

And her body was already responding to ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠his touch.

Her thighs quivered slightly, and she could feel the inside of her hot pants growing hot and wet again.

Tae-seok enjoyed her reaction and whispered even lower.

"Cleaning the table, cutting fruit, brewing coffee… at most fifteen minutes. We don't have time to hesitate."

He lifted her chin slightly and looked straight into her eyes.

"What are you talking about?"

"You want to be held."

Tae-seok's voice was sweet yet dangerous.

Kim Eun-su bit down hard on her lips.

'No… not here…'

She screamed desperately in her mind, but her body was already leaning into his embrace.

At that moment, Tae-seok covered her lips roughly.

"Mmm…!"

Kim Eun-su flinched and shrank back, but the moment his hot tongue invaded her mouth, her resistance melted away instantly.

Tae-seok pulled her waist tightly with one hand while sliding the other into her hot pants, rubbing her folds with his fingers.

"Huk…!"

Her waist trembled violently.

'No. Really… I swore I wouldn't do this again.'

After witnessing her sister having sex with Tae-seok in the kitchen, she had tried to sort out her thoughts while masturbating. No matter how good the sex with Tae-seok was, once she had seen with her own eyes that he was her sister's man, she had to cut ties with him. She had told herself that their relationship could never be more than a single mistake.

Yet the moment his body touched hers, all those resolutions blurred in an instant. His touch, his body heat, and the unknown hot energy seeping into her body were melting her reason away.

'Was I always this weak to lust? I can't even cut off one kid? How pathetic.'

Even as she thought this, she couldn't let go of the arms wrapped around his neck.

Without breaking the kiss, Tae-seok leaned her down onto the sofa and pulled down his pants, revealing his fully erect cock.

'Crazy… really… he's going to do it here?'

Even though she knew his cock would soon enter her, she didn't resist.

Rather… she couldn't.

In an instant, her pants were stripped away.

And just as expected, his cock pressed against her pussy.

The moment his member touched her most intimate place, Kim Eun-su felt an irresistible pleasure once again. She recalled the storm of ecstasy his cock had brought her the day before.

But gasping for breath, she squeezed out her last shred of reason and pushed against his chest.

"Tae-seok… if you do this to me… aren't you sorry toward my sister…?"

Her voice trembled with desperation.

Tears welled slightly in her eyes, and her lips had turned pale, amplifying that desperation.

Caught between the guilt of betraying her sister once more and the desire dominating her body, she wavered pitifully.

Yet that very sight only heightened Tae-seok's arousal further.

Instead of answering, Tae-seok rubbed his glans against her entrance and chuckled lowly.

"Of course I'm sorry. But what can I do when I want to do it with you too? And our Eun-jung… she'll understand."

Being called "noona" instead of "auntie" made her body tremble slightly.

And hearing him say her sister's name gave her a strange sense of dissonance.

"Understand… what kind of woman would understand something like this?"

"I don't know. Still… I think she would."

"Don't say such nonsense. You… really, you're going to do it? We'll get caught."

"I… don't care if we get caught."

Tae-seok truly didn't care.

It came from his confidence that she would accept his every action.

And in a way, he was curious what kind of reaction Eun-jung would show if she saw him with a woman other than herself.

His glans pushed into her pussy.

After inserting just that much, Tae-seok asked again.

"You really hate it? Tell me. We don't have time."

He spread her thighs wider, repeatedly pushing just the glans in and pulling it out.

"Haak~ Haak~ You crazy bastard… ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠this is really…"

She should have said no… but she wanted it inside so badly.

She wished he would just thrust in without asking.

But Tae-seok kept teasing her with only the glans, waiting for her answer.

"You son of a bitch… fine. Put it in."

She answered and turned her head away in embarrassment.

Tae-seok smiled faintly and thrust his hips forward.

His cock plunged deep inside her in one stroke.

"Huuuup…!"

Kim Eun-su's back arched like a bow as she forced back the moan that escaped with her hand.

The moment his cock entered deep inside her, an unknown energy rushed into her body like a storm along with it.

It was far more overwhelming than the sensation she had felt yesterday.

His thickness, heat, and the fullness filling her completely blew away what little reason she had left in an instant.

"Haang~♡ You're insane… you really put it in. You bastard…"

Gasping, Kim Eun-su clutched his T-shirt.

"What are we supposed to do now? You obviously wanted it too. You spread your legs yourself. You asked me to put it in."

With tears in her eyes, she glared at him.

"You crazy bastard… you wanted to fuck us sisters one after another? You like doing this to us?"

"Yes… I like it so much. I like it so much I'm going crazy."

"Huung… hurry… hurry up and finish. I don't want my sister to see us like this."

"Got it. I'll do my best."

Tae-seok's movements quickened.

Even though he thought it wouldn't matter if they got caught, there was no need to deliberately get caught.

Because that made it more thrilling…

"Haung…! So… good… we shouldn't… aah…!"

Clinging to Tae-seok's neck, Kim Eun-su gritted her teeth to suppress her moans.

Just then, Eun-jung's bright voice came from the kitchen.

"Eun-su, do you want your coffee… iced?"

Kim Eun-su's body stiffened instantly.

She gripped Tae-seok's shoulders tightly and barely answered in a trembling voice.

"Ah… yeah… iced is fine."

"What about Tae-seok?"

"Yes… I'll have iced too."

"Okay~"

Right after Eun-jung's voice, the sound of ice dropping into a cup with a clink and the refrigerator door closing followed in succession.

That also meant they had about one to two minutes until she brought the drinks over.

"We really don't have ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠time."

"Hurry up and cum… my heart's pounding like crazy."

Kim Eun-su pleaded in a voice that sounded like she was about to cry.

Her pussy squeezed Tae-seok's cock madly, urging his climax.

"Understood."

Tae-seok didn't hold back anymore.

His hips began moving fast and hard.

Thud! Thud! Thud! Thud!

The sofa shook violently as Kim Eun-su's elastic hips slammed against his pelvis.

"Huuung…! Hurry… please…"

With one hand tightly covering her mouth, Kim Eun-su pulled Tae-seok's hips with the other, her body trembling violently.

Tae-seok could no longer hold back and poured his hot semen deep inside her.

Spurt~

Spurt~

Spurt~

"Ugh…!"

Kim Eun-su shuddered as orgasm washed over her.

A pleasant sensation enveloped the two of them, but there was no time to savor the afterglow.

When the sound of coffee cups being placed on a tray came from the kitchen, Tae-seok quickly pulled out and pulled up his pants.

Kim Eun-su hurriedly yanked up her hot pants as well.

Almost simultaneously, Eun-jung's footsteps approached.

Seeing the two of them sitting slightly apart with flushed faces, Eun-jung tilted her head.

"What's going on? You two… why are you sitting like that? Did you fight?"

Carrying the coffee tray, Eun-jung approached the sofa and asked.

Startled, Kim Eun-su straightened up and answered as calmly as possible.

"Fight… what would I have to fight about with a kid like him? I'm just going to eat my coffee in my room."

She picked up ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠one coffee cup from the tray and stood up almost as if fleeing.

Eun-jung looked at her sister curiously before turning to Tae-seok.

"Why is she suddenly like that? You didn't really fight, did you?"

Tae-seok leaned back deeply into the sofa and smiled leisurely.

"I don't know. I don't really get it either."

He took a sip of the coffee Eun-jung had brought and watched Kim Eun-su's retreating figure.

Kim Eun-su hurriedly left the house and headed to the fitness club.

She greeted the staff as she passed the counter and went straight inside.

After changing clothes, she stood in front of the mirror as usual.

Standing face-on, she stared at her reflection for a while without doing anything.

It was the gaze of a trainer.

Not simply thinking "pretty" or "nice," but eyes that read proportions, lines, balance, and density all at once.

However.

"…Huh?"

A very subtle sense of dissonance washed over her.

A feeling difficult to explain, yet impossible to miss.

'Something's different.'

Her gaze naturally swept over her own body.

Shoulder line.

Collarbone.

Breasts.

Waist.

Hips.

Without a word, Kim Eun-su slightly lifted her training top.

Then she flexed her abs.

Clearly defined abdominal muscles.

"…Was it always this defined?"

She muttered quietly.

She recorded her body every single day.

Weight, body fat percentage, muscle mass.

Even condition, pump sensation, and fatigue levels by body part.

It was something she had done without fail every day, thinking it was only natural as a trainer.

And by those standards, the change in her body right now was…

'This doesn't make sense.'

Kim Eun-su furrowed her brows slightly.

The density of her abs.

The elasticity of her skin.

The definition of her muscles.

It wasn't simply at the level of "it got better."

It was as if…

'It got cleaned up?'

The unnecessary fat had been stripped away.

The lines had become sharper.

This wasn't a change that could be achieved through short-term exercise.

At the very least, it was absolutely not a change that could occur in a single day.