My Little Sister Is the Best F*p Material

Volume 1 Chapter 07: Using My Sister’s Friend as Masturbation Material Part 2

After being forbidden from eavesdropping by Miyu, I came downstairs to the living room and rested my weight against the sofa’s backrest.

It had been a series of sudden events since after school, and my brain, feeling overheated, was cooling down with the air conditioner’s breeze. The cold air was finally reaching my head, and I was starting to feel more alert.

Usually, my parents come home late, so it’s common for the living room to be left unattended until night. Since Miyu and I had gone straight to our rooms upon returning home, the living room, immediately after I came downstairs, was still absorbing the heat from the sun, which was high in the sky.

“Fuuu… Ah…”

Since receiving Yuka’s erotic photos, I couldn’t calm down. The live photo of the girl with her disheveled uniform pushed up to expose her breasts was on my smartphone. Every time I recognized this fact, a sense of guilt and excitement came over me, and I kept opening and closing the photo by tapping the home button repeatedly.

Although my sexual desire was building up, I still couldn’t bring myself to use these photos as masturbation material. Unlike Miyu, Yuka was a complete stranger. It was a strange situation where it was harder for me to masturbate to a stranger than to my sister, but this was my instinctive value judgment, and there was nothing I could do about it.

Masturbating to my sister’s friend was probably no different from watching an AV. Even so, if Yuka found out that her friend’s brother was using her as a masturbation aid without her consent, she would surely be outraged.

“Haa…”

My sighs kept coming, and my heartbeat quickened. No matter how hard I tried not to think about anything, the fact that I had masturbated using that photo was engraved in my body as a sense of guilt.

After trying to calm myself down and attempting to fall asleep, I don’t know how much time had passed. Eventually, I couldn’t sleep, and the stress from the restlessness in my chest became unbearable, so I moved to the kitchen. I thought drinking coffee would help me relax a little.

As I set up the coffee maker, I leaned against the kitchen counter and sat on the floor. The irregular sound of the coffee bubbling filled the living room. When I closed my eyes, the pleasant sound alone occupied my hearing, and the tension eased somewhat.

However, this pleasant sensation lasted only a few minutes. I had let my guard down completely, and my ears picked up the sound of the living room door opening, forcing my heart to endure another round of rapid, forceful beats.

“Ugh, I’m so tired!”

It was an unfamiliar voice, but I immediately recognized Yuka from the lively tone. Then, all I heard was the sound of the door closing, and it seemed that Yuka had come downstairs alone.

I had told Miyu that I was in the living room. Miyu would probably avoid running into me, and she had probably lied and said she was going to the bathroom to sneak out. Yuka seemed to find the study session as a form of punishment bothersome, and she didn’t seem likely to return anytime soon.

This was a troublesome situation. It was already awkward enough that it was my sister’s friend, but now it was a girl whose private parts I had used for masturbation without her consent.

I was reluctant to stand up, but I would be noticed anyway because of the sound of the coffee maker. If I was going to be suspicious, I might as well greet her first.

So, I stood up and caught sight of the girl across the kitchen. Yuka, who was wearing her uniform, was lying on the sofa with her legs facing me. Her knees were bent, and her skirt was hiked up, revealing her entire lower body.

And then…

“—!”

I quickly hid myself like a small animal that had encountered its arch-nemesis.

This was bad. I had seen something I shouldn’t have seen again.

No, wait. Why? How come?

— Why wasn’t she wearing any underwear!?

The lighting was just right, and the crevice was clearly visible. The slightly hairy area was undoubtedly a woman’s private part. I had seen Miyu’s naked body, but I had never seen such a clear view of a girl’s body from below.

What should I do? If I called out to her now, she would know that I had seen her private parts. Fortunately, it seemed that she hadn’t noticed the sound of the coffee maker, but if she suddenly came to the kitchen on a whim, I would be questioned about why I was hiding.

Perhaps I should make some more noticeable noise to get her attention. If I could naturally appeal to her that I had been unaware of her presence until now, perhaps Yuka would realize and close her legs on her own. Since we were not close, it wasn’t strange for me to remain silent, so I decided to act normally.

It’s fine. Just stay calm and act normal. Pretend there’s no one else here but me, and go about my daily routine in the living room like usual.

“Yuka, I knew you were here.”

The door opened with a rattling sound, and a familiar voice entered. As soon as she entered the room, her footsteps moved straight to the sofa.

Miyu had come to my rescue. What perfect timing!

“You’re not in a position to slack off.”

“Ugh! Of course I want to slack off after what you did to me!”

I heard the sound of Yuka patting the sofa. I wondered if “that” referred to Miyu taking a photo of Yuka’s breasts.

“It’s your fault for not repenting.”

“But I don’t understand what I did wrong. And it’s not like I can remember. It’s just weird that the punishment is studying.”

“Do you really not know? Or are you just not admitting it?”

“Nuuu!”

Yuka let out a strained voice and then exhaled and relaxed.

“Well, I can’t say I have no idea. If all you want me to do is apologize to Miyu, then I’ll do it. But there’s no way I’m apologizing to Haruka.”

Yuka’s voice was full of dissatisfaction. The friendly and enjoyable atmosphere had suddenly turned into something unpleasant. An inexplicable sense of anxiety began to spread in my chest.

“Hey, Miyu. Why don’t you stop listening to Haruka? I understand that you owe her a favor, but it’s obvious that she’s not a good fit for you.”

Yuka warned Miyu in a strong tone.

So, I finally heard about it. I guess this kind of thing happens in every group. On the surface, they get along, but in reality, they have a different side. I had thought that she was energetic, bright, and had no dark side, but reality was different.

What reason could she have to direct her hostility toward such a polite and cute girl? I could understand that she was jealous of Haruka’s blessed appearance, but they were friends, weren’t they? What bad thing could that girl have possibly done?

“I mean, she put vibrator inside of her during exams! No matter how you look at it, that’s just too crazy!”

I’m sorry, Yuka. That’s just too crazy indeed.

Wait, I can’t believe it. Was that pure girl hiding a vibrator in her pants and getting wet while taking a test at school? With a cool face like a doll, she was among her classmates, being watched over by the teacher, while her vagina was being dominated by a different emotion…

When I imagined it, it was an incredible act of perversion. With such a quiet appearance, how daring! Exams are pretty quiet, aren’t they? Wouldn’t she get caught?

“Yuka, don’t say any more. My brother is in the kitchen.”

“What? No way!”

I never expected this development. At this point, I had no choice but to show myself.

“Um, hello. Miyu has been in your care.”

While apologizing to Yuka in my heart for using her as a masturbation aid, I greeted her.

“Ahaha… Um, hi.”

Yuka waved her hands and made a stiff smile. After all, she had exposed Haruka’s incredible secret to me. She would surely be given additional punishment.

“S-sorry!!!”

Yuka ran upstairs to escape Miyu’s piercing gaze. Even if she ran away, I didn’t think the situation would change.

Once again, I was left alone with Miyu. Today, the awkward atmosphere kept returning. After about a minute of silence, Miyu came around to the kitchen. With an unhappy expression on her already unhappy face, Miyu glared at my swollen crotch.

“This is… well…”

It was impossible not to get excited. Haruka, who was like a beautiful doll and seemed so serious, was indulging in lewdness among the thirty-odd people.

The image of Haruka, lying face down on the desk, suppressing her moans, came to mind. I could understand that she would want to touch her sometimes. I wondered if she wiped the chair with a tissue when she stood up. No, my imagination was running wild.

“Onii-chan.”

My imagination was interrupted by Miyu’s low voice. I had received Yuka’s erotic photos instead of Haruka’s, who I was told not to use as a masturbation aid. I wanted to hold back, but this time it was impossible.

“… Was she like that?”

Ignoring my sister’s reproach, I asked.

I didn’t want to criticize her. If she explained the circumstances properly, I thought my wild imagination would stop.

“Almost everyone in the class has had that kind of experience because of Haruka.”

What an unhealthy school.

I asked, “Miyu too?” and she answered, “No, not me.” It seemed that Miyu was an exceptional existence for Haruka.

“But don’t get me wrong. Haruka can still concentrate, and since elementary school, she has been number one in her grade at school and cram school. She’s an amazing girl.”

That was amazing. It was amazing in so many ways.

A genius mind and a perverted mind were indeed two sides of the same coin.

“I was a bit taken aback when she handed me the remote control.”

Miyu muttered in a resigned tone.

You said too much, my little sister. You must have been really shocked.

“I’m sorry for making assumptions, but are you doing that kind of thing upstairs too?”

I asked cautiously. I thought I had spoken without stumbling over my words, but Miyu just glared at me and didn’t answer.

Silence means yes, right? Then, I could guess why Yuka wasn’t wearing any underwear. It wouldn’t be strange if there was some intense skinship between them. After all, they were close enough to take off each other’s bras casually.

“Don’t tell me, Miyu likes girls?”

Miyu also had an appearance that her classmates wouldn’t leave alone. So, I wondered if the reason she didn’t have any interest in boys was that she liked girls.

Miyu pursed her lips, looking uncomfortable with the question I had asked her.

However, this time she answered me.

“I don’t have those kinds of feelings for girls. Haruka is a lesbian though.”

Miyu’s voice, mixed with a sigh, revealed her true feelings. It seemed that she had no sexual interest in girls, at least not to a significant degree.

“Is that so? I thought so because you were defending her so much.”

“I have no intention of explaining that reason to you. Just forget about Haruka completely.”

Miyu knelt in front of me again, creating the same scene as earlier today.

“Today, you’re not allowed to be in a horny mood. I’ll take care of everything, so if you get aroused, just let it out right away.”

Even though I was urged by Miyu, I was still hesitant to take off my pants. I was excited, but I didn’t feel like I could masturbate. If the atmosphere was a little better, it might have been different, but Miyu’s mood was not good, and I felt like I was losing my erection.

“It seems difficult right now.”

“But it’s so big?”

Those words echoed in my penis.

“Use Yuka’s photo.”

I was ordered by Miyu, and I opened Yuka’s erotic photo again. However, men were not that simple, and I couldn’t ejaculate just by looking at the photo.

“Mou…”

I wasn’t going to ejaculate just because of that pout. It was much better than the scary face she had made earlier though.

I stood there without even unzipping my pants. Meanwhile, Miyu was thinking hard, and a few minutes passed. Then, Miyu sighed once and stood up with a determined look on her face.

“I’ll get ready, so wait for me.”

Miyu returned to the living room and started rummaging through the drawers, looking for something. I remembered that that area was where she kept her sewing tools.

“What do you mean by getting ready?”

I asked, but Miyu, in this mood, was not going to tell me.

“I’ll come and get you when I’m ready. Until then, don’t think about anything sexy, okay?”

Miyu warned me like that, holding a white cloth and nylon tape, and went upstairs.