40. The Only Thing That Can Satisfy Mother-in-Law's Frustrated Cunt Is Her Son-in-Law's Massive Horse Cock. "Isn't Hye-jin Pretty?"

Watching Seo Hye-jin bickering with their mother, Seo Mi-na turned to Geum Tae-yang beside her and said, "She is. Overflowing with charm. But I don't think Sister-in-law Hye-jin realizes it herself."

"That's what makes her even more attractive. The fact that she doesn't know how pretty ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠she is, yet carries herself like that."

Geum Tae-yang agreed. Though all four sisters had overwhelmingly strong personalities, Seo Hye-jin stood out as uniquely distinct. And now that she'd entered college, with her short, dyed hair, that uniqueness had only intensified. "Looking at her, I finally understand why Mom married Dad."

The source of Seo Hye-jin's uniqueness—compared to Seo Mi-na, Seo Da-hye, and Seo Ji-eun—was that she resembled their father just a little more. My little sister really is captivating... dangerously so...

That magnetic allure—wasn't it born from something other? That was exactly the kind of relationship Kim Seo-yeon and Seo Min-jun had. The moment she discovered her younger sister Seo Hye-jin, face pale after catching her and Geum Tae-yang mid-fuck,

Seo Mi-na—her primal feminine instincts surging—felt firsthand the beauty of that otherness Kim Seo-yeon must have experienced in her youth. Sorry, but this man is mine, okay?

If they had been different genders, would it have been love? But since they were undeniably the same sex, the deranged Seo Mi-na felt something else entirely. Competitiveness. The drive to not let another female—one with that other kind of allure—steal her man. "Schlurp! Schlurp! ♡ Nghh—my man... Hahhhh! Ngh! Schlurp! ♡ My male... Hrrrlp! ♡ Chuuurp! ♡"

Bounce♡ Bounce! Shake! Bounce♡ Shake! ♡ Bounce! Bounce! ♡

"Grrruuuuh...! I can feel my woman's insane obsession!"

And so, the unhinged artist Seo Mi-na—

as if performing an act of live art—

instead of ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠stopping after being caught fucking her future husband by her sister, only grew more frenzied, rocking her hips wildly, milking the massive cock buried in her cunt. 'Wh-what's wrong with you, unnie...? What's with that look...?'

Shake, shake, shake—

Seo Hye-jin was the classic tough-on-the-outside, soft-on-the-inside type. A fighter, but also quick to tears and empathy. Especially when it came to family—that was her weakness. Under her sister's intense, unhinged gaze, her hands trembled as if she were terrified. 'I'm your little sister... not your rival...'

She knew exactly what that look ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠meant. Having attended elite schools, she'd both experienced and witnessed fierce competition—especially the raw, physical kind. Her sister's eyes, warning her as a female rival,

and the victorious glint declaring, This male is already mine,

were so unfamiliar, so impossible to rationalize, that Seo Hye-jin was utterly frightened. "That's right! I'll make sure you know I'm your man and you're my woman!! I'll fuck it into you!"

WHAM!"Hhaaahhhhk! Hhiiihhhhk!"

—THUD!! Geum Tae-yang seized Seo Mi-na's small head and slammed it down. For some reason, she craved overpowering domination right now. So he'd give it to her. There was nothing he wouldn't do for her. "Hhaaaaah!"

—RIP!! The sight of her once cool, charismatic eldest sister now being brutally dominated—

Seo Hye-jin staggered back, panicked. She had taken a single step into the room through the open door, but now she retreated. "Let's make sure our Mi-na sees it properly! The moment my cum floods your cunt!"

THWACK!"Hhaaahhhhk! Hhiik! Hhngguuhhk!"

Shake! Shake! Shake! Geum Tae-yang had no intention of just dumping his load in a simple doggy-style fuck. He wanted to show his dominance. So from that position, he lifted one of Seo Mi-na's legs—a twisted variation of sideways penetration, almost like a puppy pissing. Despite having fucked Geum Tae-yang hundreds of times, she had never been in such a crude position before.

Seo Mi-na convulsed, shaking her head frantically. "Too late! I'm gonna pump you full and cum! I'm already on the edge! Take responsibility for the orgasm you pulled out of me!"

Plunge! Plunge! Squelch! Plunge! ♡ Squelsh-squelch! ♡ Plunge! Plunge! ♡

"Nnghhaaahhk! Kuhhk! Hhngguuhhk! Tuhh! Hhnghhaaahhk! Hhngk!"

Slap! Slap! Slap! Slap! Geum Tae-yang knew. If Seo Mi-na truly didn't want it, she had the strength to stop the sex outright. Meaning her frantic head-shaking now? That was just shyness.

Geum Tae-yang thrust vigorously into Seo Mi-na's pussy in the doggy-peeing position, unloading his cum with forceful strokes. 'She's not even wearing a condom! If I finish inside her like this, she might get pregnant! Are you trying to speedrun this?!'

Shiver, shiver, shiver...!! From just 2.5 meters away in the bedroom doorway, Seo Hye-jin trembled like a leaf, completely overwhelmed by the raw intensity of the sex unfolding before her. "Cum inside me! Hnggh! Kkhh! Hnngh! It's a safe day! Hnngh! Hhht! Hahh! Fill me up, Tae-yang! Nnghh!"

"Damn it! I was trying to knock you up!! I was gonna do it raw!! Why'd it have to be a safe day?!"

Squelch, squelch, squish! Plap, plap, glurk! ♡ Squish, plap, plap, glurk! ♡

"Hhaaahh! You beast! Hahhhn! Tkhhaaahh!"

Rock, rock, rock! ♡ Rock! ♡ Shake, shake! Rock! Shake! ♡

'Brother-in-law's gone insane!!'

Today just happened to be Seo Mi-na's safe day, and Geum Tae-yang put on a frustrated, thrashing performance—one that Mi-na seemed to enjoy, meeting his rapid-fire thrusts with equally wild hip swings.

Meanwhile, the naive Seo Hye-jin, taking his words at face value, panicked. "He's serious! He's gonna fill the very pussy and womb that'll carry my child soon!"

Thud! Glug—Splurt! Sploosh! Sssplsshhh!! ♡♡♡

With that, Geum Tae-yang buried himself deep in Seo Mi-na's doggy-peeing-positioned buttocks, parking his shaft firmly against her groin before unleashing a flood of scorching cum.

"Hkkyyaaahhh! Khhh! Hhaaahhhnn!!"

Sssqqquuuiiirt!! Splurt! Sssplsshh! Spllloorrch! ♡♡♡

"Brother-in-law's gone completely insane!!"

Today was supposed to be Seo Mina's safe day,

but Geum Taeyang put on a performance of frustrated struggle as if deeply disappointed. Enjoying this, Seo Mina retaliated against his lightning-fast premature ejaculation tendencies with her own counterattack of vigorous hip thrusts,

while the naive Seo Hyejin, having taken her brother-in-law's words at face value, panicked. "Thirty-five! Soon my baby-making pussy and womb will—!"

Squelch! Glug-glug! —Splurt! Gush! Splish-splash-splurt!! ♡♡♡

Geum Taeyang, having deeply parked himself in Seo Mina's puppy-style upturned buttocks and inner thighs, now sprayed his hot cock juices wildly,

"Hngyaaaaah! Cough! Hahaaaaaah!!"

Sluuuurp!! Splurt! Splish-splash-squirt! Dribble-dribble! ♡♡♡

Seo Mi-na arched her back like a drawn bow,

let out a beastly cry,

and at the same time she sprayed musk like a skunk all over Geum Tae-yang's body, she climaxed. —Dodododododo! Semen and musk splattered everywhere,

as Tae-yang and Mi-na continued their afterplay, groping each other's bodies and exchanging kisses. Behind them, Seo Hye-jin hurried down from the second floor and rushed out of the house. 'Hwaaaa! They're insane! Both of them are insane!'

Staggering like she'd seen a ghost, she muttered under her breath.

"Huuuuu... Tae-yang, while tasting your cock countless times, I had a thought... Haahhh..."

"Don't think... Schlurp...! Mi-na, I think it's better if you don't think at all... Schluuuurp...!"

Squish...! Squish...! Squish...!

"Listen... It's kind of serious..."

Meanwhile, in the Second Master Room, Seo Mi-na, now fully satisfied, panted heavily and started running her mouth again. And Tae-yang, while kissing her and fondling her breasts, continued to take responsibility for his beloved woman's afterplay.

"Maybe our mom... was sexually frustrated the whole time she was with Dad..."

"Tch... What kind of crazy ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠nonsense is that, you ungrateful brat, Mi-na..."

Slap! ♡ Smack! ♡

"Haaahhh...! ♡ Hngg...! ♡ So good..."

Mi-na proposed a rather novel hypothesis.

"Think about it, dummy... Mom has an even more incredible body than mine... Do you really think a normal-sized cock could satisfy her...? Huh? Am I wrong? Can you deny it? Absolutely not, I bet... Hngggg..."

"Shut up! Just don't say anything! Just scream like the ungrateful brat you are, Seo Mi-na!"

Thrust! Splurt! Thrust! Thrust! Thrust!

"Haaahhh! This cock right here! T-haaahhh! Hngg! This inhuman monster cock! K-haaahhh! Hahh! Haaang! It has to be at least this big! T-hnggg! Haaahhh!"

Her hypothesis was that her mother, Kim Seo-yeon—possessing the ultimate sex physique—had likely never been satisfied by her father, Seo Min-jun, throughout their marriage.

Tae-yang punished the outrageously disrespectful Mi-na by ramming his massive cock into her mouth with full force, while Mi-na felt with her entire body that her theory couldn't possibly be wrong.

"Kyah! Working out here definitely gives a more intense burn, sis-in-law."

Later, after another round in the shower, Mi-na hurried off to meet her advisor.

Once she confirmed her sister's car had left, Hye-jin returned and, as planned, arrived at the training center with Tae-yang. It was a gym run by one of Hye-jin's acquaintances, with an atmosphere as shabby as an underground warehouse—which was exactly her intention. Her philosophy was that anything too flashy would negatively impact workout performance.

"Circuit training is absolutely brutal. At least now it's somewhat manageable."

Tae-yang crushed his weighted pull-ups. The Ceremonial Security Team's gym training focused on circuit programs, so he balanced it out with regular weight training when working out with Hye-jin.

'Even when holding back, he pulls off pull-ups like that... Well, with that ass, it's no surprise...'

Though Tae-yang chatted eagerly to bond with his sister-in-law, Hye-jin didn't hear a word. Her eyes were glued to his ass from behind.

"What are you doing, sis-in-law?! It's the last set of 10! Spot me properly!"

"Ah! I lost count."

Her mind was completely elsewhere, having witnessed the reality of her brother-in-law firsthand.

Thud! Thud!

As she had for weeks, Hye-jin braced Tae-yang's lats to support him.

'The way his lats flared wide when he gripped unnie's ass like he was about to tear it apart...'

The moment her hands touched the vast expanse of Tae-yang's lats,

a different train of thought ran through Hye-jin's mind. Before, she would've focused on whether his lats were properly engaged in the pull-up.

Now, all she could picture was the beastly, pumped-up, split-open version of him during sex.

"Are you even holding me?"

"Ah! Y-Yes, I've got you, brother-in-law..."

What kind of image was it? The image of a tetoman that cowed Hye-jin.

Instinctively, her grip weakened.

Unaware of the situation, Tae-yang complained that her support seemed off.

"Hngghhaaa...! Ughhaaa...!"

Geum Tae-yang exhaled a deep breath from his dantian as he powered through his final weighted pull-up. Brother-in-law's breathing was always this obscene? Even his sweat smells too stimulating...

Neither Geum Tae-yang's exertion-heavy breaths nor his pheromone-laden sweat were the same to Seo Hye-jin anymore. Before, they had simply registered as proof of his hard work—pure and uncomplicated. Now, they felt feral, too raw. The reason was obvious: they had been overwritten by the new versions—the ones that had assaulted her eardrums and seeped thickly from the bedroom during his sessions with her sister. Get a grip. Noona is so composed and rational.

It was intoxicating to the point of delirium. Flushed crimson, Hye-jin floundered, conjuring the image of her eldest sister, Seo Mi-na.

[I] Noona... I saw it...

[Big Sister with Elastic Breasts] I know. We made eye contact, didn't we?

Of course, Hye-jin had messaged Mi-na before re-entering the house.

[I] And that's your reaction?

[Big Sister with Elastic Breasts] Obviously. You saw your future brother-in-law and me having sex—so what?

[Big Sister with Elastic Breasts] Besides, you're an adult. Why make a fuss?

[I] Ah...

Unlike her, Big Sister Mi-na was terrifyingly unshaken.

[I] Still, your reaction earlier was weird...

[Big Sister with Elastic Breasts] What reaction?

[I] You barely even flinched...

[Big Sister with Elastic Breasts] Ah~

Hye-jin was simple. When faced with conflict or discomfort, she confronted it head-on, talking it out to resolve things.

She had cautiously alluded to the unsettling vibe she'd gotten from her sister.

[Big Sister with Elastic Breasts] If I'd panicked, your brother-in-law would've noticed.

[Big Sister with Elastic Breasts] Then how awkward would things get between you two?

[I] Oh... Right.

[I] Noona, you're amazing. To make that call in that situation...

[Big Sister with Elastic Breasts] That's why I'm the one getting married. Hurry up and get wise like me.

[I] ......

When it came to her beloved Tae-yang, Mi-na was undeniably the apex predator of the household. With flawless logic, she had rationalized what should've been an absurd scenario. And yet, that same Noona becomes the submissive one in bed with him...

Mi-na's immaculate handling of the situation only elevated Tae-yang's standing in Hye-jin's eyes. Noona hadn't changed. Big Sister was still as charismatic and sharp as ever. But in the raw truth of intimacy with him, she became the submissive. That could only mean one thing: Brother-in-law was far more dominant, far more alpha than Hye-jin had ever imagined. So that's the beast hiding inside him...

Having assisted Tae-yang with his weighted pull-ups, Hye-jin's gaze drifted toward the bulge in his training shorts.

"Focus, Sister-in-law. Bench press is dangerous if you're distracted."

"Got it. Don't worry, Brother-in-law."

Positioned above Tae-yang as he lay back for bench press, she had a direct view of his lower half. No wonder he took so long to get ready... How much adjusting did he have to do to hide that monster...

But there was no trace of the 16cm silhouette she'd witnessed in her dream. He had prepared thoroughly. Guilt pricked her for complaining earlier about how long he took to get ready for the gym. He'd been considerate—of her. Consideration...

Yes. Though strong enough to dominate the family's fiercest, Tae-yang never flaunted it. He tempered himself, considered others, to harmonize with them.

"Hwa! What do think, Sister-in-law? Brother-in-law's abs aren't half bad, right?"

Finishing his set, Tae-yang struck a pose, proudly flexing his sculpted abdomen.

"Hmm..."

Then his expression shifted to concern.

"Sister-in-law, are you feeling okay today? You're quiet, and your face looks pale."

His earlier bravado had been deliberate. Hye-jin wasn't acting like herself. Normally, she'd be needling him, pushing him harder during workouts. But now she seemed dazed, lost in thought.

"N-No, Brother-in-law... I'm fine..."

Her response only made it worse. Mumbling, she averted his gaze entirely.

"You don't look fine. Your face is flushed—do you have a fever?"

Sssk—!

The moment Tae-yang voiced his concern, Hye-jin's cheeks burned hotter. Assuming she might be feverish, he reached out, pressing a caring palm to her forehead.

Ah...!

As his warm, gentle hand made contact, Hye-jin's eyes widened.

H-His hand... It's so warm...

No man had ever touched her forehead like this—not even her father.

Hhk—!

In that instant, as if drawn by some invisible force, her eyes flicked back toward Tae-yang.

!!!

! '

Her eyes widened even further then,

"Hmm... You might have a slight fever, or maybe not?"

Because Tae-yang had leaned in slightly with that caring gaze of his, his face etched with concern. 'Ah... Aaah... What is this...?'

Thump! Thump! Thump!

This was, without a doubt, the same brother-in-law who would soon marry her sister—the same man who, just hours earlier, had been rutting like an animal with her sister—

Yet Hye-jin felt an inexplicable pounding in her chest, one she couldn't even begin to rationalize.

**********

"I'll live well!!!"

And so, overcoming the final hurdle in an unexpected turn of events, Geum Tae-yang finally held his wedding in mid-September.

"Congratulations, unnie! Brother-in-law, I truly congratulate you!"

"Wow! Our unnie looks like an angel!"

Amidst the blessings from family and—

"Tae-yang, you're getting married before me? I respect that!"

"Uncle Tae-yang! You have to live happily, okay? And you have to keep your promise to me!"

"Thank you, Myeong-ho hyung!! Hahaha! I appreciate it, So-min. Later, I'll take your unnie's hand and we'll go eat lots of delicious things, okay, So-min?"

—the well-wishes from those around him,

Geum Tae-yang proceeded with the wedding.

And afterward, a thought settled uneasily in his mind:

'Wait... could it be?'

A strange suspicion began to take root in his heart.