Chapter 400 (Mom)
Translator: RaidenTL
Chapter 400 (Mom)

That morning, Si-woo had chosen a loose-fit purple t-shirt for his mom to wear.
He had strictly commanded her not to wear or drape anything else over herself except for that specific purple t-shirt.
He had already told her a long time ago that she wasn't allowed to wear underwear inside the house...!
Unless told otherwise, Mom always had to spend her time at home without any underwear on.
The command to live without underwear was originally intended for when she was at home; he hadn't even considered the possibility of her going out.
Si-woo had assumed that while he was at the department store with his sisters today, Mom would remain inside the house, dressed exactly as he had instructed.
However, instead of the purple t-shirt Si-woo had put on her, Mom had changed into Se-hee Noona’s apricot-colored t-shirt before leaving the house.
It was a similar apricot-colored, loose-fit long t-shirt that looked almost identical to the one he had chosen, save for the hem being slightly longer.
Had she picked the most similar item from Se-hee Noona’s clothes hanging on the drying rack in the changing room because the purple one had been soiled during their mother-daughter activities?
Si-woo hadn't expected at all that Mom would go out to the mart to shop while he was at the department store with his sisters.
He understood that the command to not wear underwear was fundamentally meant for inside the house, so her wearing it outside might have been unavoidable...
Still, the fact that she had changed clothes and gone out without his permission, and without even contacting him via text or call, weighed on his mind.
* * *
If she was going to take off the purple t-shirt he told her to wear and change anyway, she might as well have dressed properly...
But the clothes Mom was wearing now were of a length where her lower half wasn't clearly visible, hidden by the hem of the t-shirt.
Until they arrived at the karaoke room, Si-woo had naturally assumed she would be wearing underwear and bottoms beneath the t-shirt, perhaps with more layers on top. Now, a question mark popped up in his head.
To match an apricot long t-shirt, she should have worn something like short pants or a short skirt underneath.
Knowing Mom’s usual style, it was hard to imagine her choosing such an outfit.
In the first place, Se-hee Noona’s skirts wouldn't fit Mom’s size, and there was no way Mom’s wardrobe contained the kind of clothes Se-hee Noona would wear.
Yet, the hem of the t-shirt was far too short for her to be wearing any other suitable bottoms.
Suddenly, a surge of pleasure, like squeezed juice, spread through Si-woo’s chest.
He recalled Mom’s awkward posture and stiff movements from the mart all the way to the karaoke room.
When he first spotted her in front of the mart, she had been standing there, seemingly conscious of the eyes around her, covering her breasts with one arm and pulling down the hem of her t-shirt as if trying to stretch it.
Could it be that Mom wasn't wearing any bottoms under that thin t-shirt right now?
Not just bottoms, but perhaps not even any underwear?
With a sense of anticipation, Si-woo scanned Mom’s body as she sang at the top of her lungs.
Around Mom’s neck, she was still wearing the red leather dog collar.
The red leather dog collar with a tiny yellow bell dangling from it.
That dog collar she wore was now nothing less than a mark proving her status as a slave among Si-woo and the family.
As she sang, Mom was covering her large breasts with one arm.
Why had she been doing that for a while now? She wasn't moving violently or jumping enough for her breasts to bounce.
Every time Mom’s body moved to the beat, the fabric of the loose t-shirt clung to her buttocks, causing the two smooth mounds to appear and disappear repeatedly.
He couldn't confirm whether she was wearing underwear just by looking, but the thought that she might have nothing on under her clothes made Si-woo’s cock throb and twitch.
* * *
Contrary to her outward attitude, Mom had always faithfully followed Si-woo’s commands until now.
More than any words or signs, Mom’s diligent obedience to his orders stimulated Si-woo’s expectations and curiosity regarding her attire.
The first song playing from the karaoke machine was already past its midpoint.
While still seated, Si-woo carefully raised his arm and reached toward her body.
He placed his hand on her waist, just above her buttocks.
The moment Si-woo’s fingertips touched her waist, Mom’s buttocks flinched with tension, and her body jerked as if stiffening.
Consequently, her voice wavered slightly, losing the note as she sang.
She turned her head to look back for a moment, but when her eyes met Si-woo’s, she quickly looked forward again, appearing flustered.
Though her buttocks and waist were stiff with discomfort, she continued to sing.
Even as Si-woo’s fingertips pressed against the top of her buttocks...
Mom continued singing along to the accompaniment from the machine, seemingly ignoring his actions.
It felt as though Mom was giving her implicit approval or consent for Si-woo to check if she was wearing underwear.
Si-woo pressed his index finger firmly against one of Mom’s buttocks, right where the soft curve began.
Just as he had done on the subway before, Si-woo intended to trace a line across Mom’s buttocks with his finger to check for underwear.
Slowly, Si-woo traced a diagonal line across one of her buttocks.
His finger followed the voluminous curve of Mom’s tensed backside, moving diagonally toward her outer thigh.
His finger didn't catch on anything like an underwear waistband.
Just like last time, Mom wasn't wearing panties today either.
Furthermore, just like last time, she was condoning Si-woo’s molestation in a public place.
Even if it was a closed-off space...
As he traced her skin, the flesh of her smooth buttocks quivered, and the pitch of her singing wavered once more.
Even in that situation, Mom stood there, wrapping her other arm around the shoulder of the arm holding the microphone, as if to hide a specific part of her breasts.
It was certain that Mom wasn't wearing a bra either.
The red dog collar—the mark of a slave—and Se-hee Noona’s apricot long t-shirt.
Aside from the shoes on her feet, it was safe to assume Mom had nothing else on her body.
Though she had been grumbling and nagging Si-woo about the things he made her do or wear, Mom was actually following every single one of his commands without fail, maintaining their master-slave relationship.
Her contradictory attitude, which caused him so much worry and unnecessary thought, felt somewhat spiteful, yet at the same time, he found it cute and even a bit pitiful.
Gaining confidence, Si-woo fully opened his palm and boldly cupped one of Mom’s buttocks.
Mom’s flesh shook and jolted for a moment.
This time, she didn't look back and kept singing.
Si-woo moved his hand gently to the melody and rhythm of the song.
Mom’s buttocks, covered only by a single layer of thin t-shirt fabric, were being rubbed by Si-woo’s soft touch.
Mom stopped moving to the rhythm altogether and stood still, singing with her buttocks clenched tight in tension.
Si-woo extended his index finger and traced the crack of Mom’s buttocks from top to bottom over her clothes.
The fabric of Mom’s t-shirt was buried deep into her crack along with Si-woo’s index finger.
The tip of Si-woo’s finger, thrust deep inside, touched Mom’s anus.
Mom’s mounds on both sides clenched hard, pressing against Si-woo’s finger.
Si-woo slowly rotated his index finger between the cheeks of her buttocks before pulling it out.
Mom’s voice now contained more sound of breathing than actual notes.
Mom had been clenching her buttocks so hard that even after Si-woo removed his finger, the t-shirt remained wedged between her mounds.
'Is this bitch just a masochist by nature?'
The moment Si-woo applied a little pressure and pushed her, the sharp, nagging attitude she had shown moments ago vanished without a trace, and she performed her role as a slave bitch perfectly.
A sadistic instinct seemed to surge from deep within his chest.
Si-woo picked up his camera and took a photo of Mom’s humiliating buttocks with the t-shirt wedged inside.
Click! Click! Click!
In the dark, flashy lighting, her buttocks—illuminated by the smartphone’s flash—were captured on Si-woo’s screen.
With every shutter sound, her buttocks twitched with the t-shirt still wedged in the crack.
While the t-shirt was still stuck between her cheeks, Si-woo lifted the bottom hem of the shirt.
The mounds of her buttocks and the dark hair of her groin were exposed starkly beneath the wedged fabric.