Rin Ito sat at his computer, drawing Suzu's seductive eyes, but he wasn't sketching Suzu for the manga; he was simply using her alluring gaze during their teasing as a reference.
Meanwhile, just two curtains away in Suzu's room, Rin's girlfriend, Kaede Hoshizuki, was getting off while wearing the black pantyhose that Rin and Suzu had soiled, taking advantage of Suzu's shower time.
The sheer nylon material was thin and quick to dry. The pantyhose, recently discarded by Suzu, had almost air-dried, but now...
"Ugh... Mmm...!!!"
Faster, faster, faster... Suzu would be back from her shower soon!
Because she was in Suzu's room, Kaede—sitting on the floor with her back against the bed—didn't allow herself to slowly enter the state of arousal as she usually would. However, the anxiety and thrill of possibly being discovered in Suzu's room made her body even more sensitive.
The forbidden act combined with the intense pleasure caused Kaede's expression to become hazy.
Through the thin black nylon, Kaede skillfully found the budding clit and roughly rubbed it, quickly causing the pantyhose to be stained wet once more.
"Woooah!!!!"
A short moan escaped from her lightly bitten lower lip. After a few seconds of full-body tension, she went slack. Her eyes slowly cleared from the hazy state, and Kaede clearly realized what she had just done.
She came...
In Suzu's room, wearing pantyhose soiled by Suzu and Rin...
She was his girlfriend, yet she had to secretly wear her sister's dirty pantyhose to satisfy herself.
This humiliating reality echoed in Kaede's mind until footsteps approaching from outside snapped her back to attention. She quickly stripped off the pantyhose and tossed them under the bed, hurriedly pulling on the shorts she wore as pajamas.
After all that, Kaede grabbed her phone and sat on the edge of the bed, pretending to be scrolling.
"You showered fast." Kaede, who had almost forgotten to breathe from the tension, mechanically scrolled her phone screen. Although she had changed into her pajama shorts and wiped herself, Kaede felt like something was still running down her thigh.
"Mhm."
Suzu nodded, picked up her phone from the stand, hit 'Save Recording,' and then subtly glanced at Kaede pretending to play on her phone.
"Did you enjoy my pantyhose?"
"!!!!"
Kaede felt her heart stop. Her cheeks, still flushed, instantly turned pale as she stammered a denial.
"Wh-What are you saying? I... I would never use your pantyhose to get off!"
Before the trembling Kaede could fully react, Suzu reached under the hem of Kaede's shorts, gave a light swipe, and then held the wet fingertip up to Kaede's face.
"What is this?"
"That's sweat! S-Sweat... Y-Your room is too hot, and I just showered, so I'm sweating."
Seeing Kaede still lying, Suzu handed Kaede her phone.
The screen showed a video of Kaede getting off while wearing Suzu's pantyhose. Suzu then pulled the pantyhose out from under the bed and displayed the sticky part right in front of Kaede.
Kaede completely froze... Faced with irrefutable evidence, she had no way to argue.
Her brain raced.
What should I do, what should I do, what should I do?
She was Rin's girlfriend, yet she was using pantyhose soiled during her sister's cheating to satisfy herself...
Wait!
"You... how dare you bring that up! What is this? Don't tell me you did this yourself. Rin... Rin is my boyfriend!"
Kaede pointed at the stain on the pantyhose, her tone a façade of authority masking her terror.
Kaede didn't actually want an answer from Suzu; she just wanted to change the subject.
"Because I like him too," Suzu paused. "Besides, Kaede, don't you enjoy it?"
"Of course I like him..."
Kaede's sentence was cut short by Suzu.
"I mean, don't you enjoy being cuckolded?" Suzu stared into Kaede's eyes, her tone flat.
"I... er... Wh-What nonsense are you talking about!?"
Kaede forced a straight face and used the same feigned authority. "How could I possibly enjoy being cuckolded?"
Even if she read Reverse-NTR manga and got off wearing pantyhose soiled by her sister and boyfriend, she was a good girl!
She was only doing this to complete a system mission for his Protagonist Nurturing!
She definitely did not have a cuckold fetish!
"Is that so?" Suzu paused again, then pulled out her trump card. "I have Kaede's browser history, you know."
"...."
Kaede cared more about her sister than her own dignity.
As the older sister, Kaede understood Suzu well... Suzu's love for Rin was no less than her own.
Although they had an intimate encounter, it must have been Suzu who took the lead, and she probably used some means to threaten him; otherwise, the usually rule-abiding Rin would never cheat.
Suzu rarely spoke and didn't show much emotion, but she was a frequent teaser, and Kaede was always the one being teased growing up.
It was actually through Suzu's teasing that Kaede finally confessed to Rin; in a way, Suzu deserved some credit for Rin choosing Kaede.
Although Suzu also liked him, other than today, she hadn't done anything inappropriate since Rin made his choice.
Suzu must have secretly slept with Rin today because she found out Kaede was reading Reverse-NTR manga!
Combined with Kaede's recent habit of bringing female classmates home for him... Suzu must have thought Kaede had a cuckold fetish, which is why Suzu secretly initiated intimacy with him today.
Kaede didn't know how Suzu felt when she set up the chance for the tsundere Kaede to confess, but... Suzu helped her then, and now it was her turn to help Suzu!
If Suzu hadn't thought Kaede had a cuckold fetish, she would never have seduced Rin.
If Kaede admitted to the fetish, Suzu could confidently seduce and secure him, and the three of them could be together forever.
...
Furthermore... the Nurturing System restricted Kaede's contact with Rin.
She could only KISS him after another girl had KISSed him, and she could only sleep with him after another girl had slept with him.
But that "other girl" could be Suzu!
It was a System loophole!
Kaede had no interest in Rin cheating on her, but Suzu was the exception.
This way, Rin wouldn't have to cheat, and he and Suzu could be together guilt-free. In exchange, Kaede only had to admit to a cuckold fetish in front of Suzu. That was hardly a price at all.
Although it was humiliating and Suzu might mistake her for a pervert, for her sister's happiness... and definitely not because of the video on Suzu's phone and her browser history!
"Y-Yes, that's right. I do have a cuckold fetish. The thought of him with another girl... it excites me. And seeing those pantyhose that you and he soiled... I... I just couldn't resist. Ugh... I'm a pervert with a cuckold fetish!"
Hearing Kaede's 'confession,' Suzu's eyes lit up.
"It's okay," Suzu gently hugged her sister, who was almost crying from shame. "It's okay to have strange fetishes. I'll help you!"