My Little Sister Is the Best F*p Material - Volume 3 Chapter 3: Worried Sister, Unbothered Brother

Volume 3 Chapter 03: Worried Sister, Unbothered Brother

There were four placemats laid out on the table. Plates were placed on three of them, for me, my mother, and my father.

Today’s breakfast was bread, with each of us adding our favorite toppings. My parents went for a pizza style, with ketchup and cheese. I went for the more traditional option, with margarine and jam, or sometimes just sugar. Miyu often ate it with salad or a fried egg on top.

“Ko-chan, we’re leaving for our trip tomorrow. Please take care of Miyu for me.”

“Hmm, okay.”

I took a bite of my bread and turned my attention to the stairs outside the living room. It was still a school day, yet Miyu hadn’t come down for breakfast.

“She’s usually very responsible, but sometimes she lets her guard down over small things. Be careful and make sure she doesn’t have any accidents.”

My mother, who had already finished her breakfast, was hurriedly checking the contents of her work bag.

As my mother said, Miyu does have her clumsy moments. Miyu is like a regular girl wearing a perfect mask. She wasn’t born a genius, but has worked hard to get where she is now. Miyu’s calmness is probably a result of the tension she has built up through her efforts, and if that thread were to break, she would become a weak girl instead.

There was no doubt in my mind that the reason Miyu hadn’t come down for breakfast was because of yesterday’s health check. Miyu, who was complexed about her breast size, was troubled by the fact that her bust size had finally reached the nineties. The shock must still be affecting her. Miyu wouldn’t miss enough days to affect her attendance, but if I didn’t wake her up, it would feel like I was ignoring her, and that would leave a bad taste in my mouth.

I decided to finish my meal quickly and go to Miyu’s room. I couldn’t just barge into a girl’s room, even if she was my sister, so I knocked on the door, but there was no response.

I opened the door and peeked inside. The futon was piled up like a manju.

It seemed she hadn’t even started getting ready for school.

“Miyu, it’s morning.”

Even when I spoke to her, there was no response. From yesterday’s incident, I knew that Miyu was extremely difficult to wake up when she was tired.

I entered Miyu’s room and closed the door. The interior was the same as before, with a simple yet girly reddish color scheme. However, the floor was unusually messy, with clothes and beauty products left out.

“Wake up, Miyu. You’ll be late for school.”

I shook Miyu’s shoulder, which was sticking out from the futon.

“Nn… Nnyu…”

Miyu stuck out her second joint from the futon and lowered the blanket to her eyes. Her face, which looked like she was squinting in the bright light, seemed annoyed.

“You won’t have time to eat breakfast if you don’t get up soon, so I came to wake you up. If you want to skip school, that’s fine, but what do you want to do?”

“I… I’ll go.”

Contrary to her words, Miyu covered her head with the futon again. She was in bad shape. Usually, Miyu was very meticulous, so the contrast showed just how shocked she was.

“This morning’s breakfast is bread, so if you want to eat it in your room, I’ll bring it for you.”

Miyu didn’t like eating in her room because she was worried about the floor getting dirty or the smell sticking to the walls, but if I made it so it wouldn’t spill, she would probably eat the bread. She sometimes brought cocoa with her when she studied.

Miyu showed her face again when I made my proposal. Her usual lovely eyes had returned.

“That’s nice, but I don’t feel like eating.”

So that’s why Miyu had slept in so late. If she wasn’t going to eat, then of course she had plenty of time to get to school. I guess I’ll go back and clear the dishes.

Just as I was about to leave the room, I felt a sense of discomfort at the foot of Miyu’s bed. I heard Miyu get up behind me, and as she pulled back the futon, the source of my discomfort was revealed.

A pale orange panty was lying there. The shoulder straps of what was presumably the matching bra were sticking out from under the futon, and the hem of her pajamas was visible beyond that.

A premonition flashed through my mind. No, it was already a certainty, and it had robbed me of my consideration out of curiosity.

“Ah…”

Miyu and I realized it at almost the same time. Miyu’s body, which had risen from the futon, was shining white in the morning sun. Her upper body was mature, which was the source of her worries, and at the tip, a pale pink bud was blooming.

“Uu… I forgot…”

Miyu covered her body from the neck down with the futon. I could understand the meaning of her words, even though she didn’t say them. There was no other way to interpret it.

My imagination, which wouldn’t stop, gathered heat in my lower body. The clothes that had been taken off in the futon… If she hadn’t been wearing them from the start, it wouldn’t have been a big deal, but Miyu had taken off what she was wearing and become naked. I knew it was unlikely, but there was only one fact that this could point to.

“Onii-chan…”

Miyu’s voice, filled with resentment and shame, reached my ears. It strengthened my certainty even more, and gave my penis even more hardness.

“It’s because, when I was sleeping, the bra that didn’t fit was uncomfortable. So, I just took it off…”

Miyu’s desperate excuse became quieter and quieter. Since Miyu’s body was only growing in her chest, there was no reason to take off her panties just because her bra was getting tight.

My silence was my answer. Miyu seemed to be desperately looking for a good excuse, but there was no way this situation could be reversed.

“I-I also have times when I have too much energy in my young body.”

Miyu finally admitted it.

That she had comforted herself alone last night.

I couldn’t hear her voice at all. Miyu must have been suppressing her voice so I wouldn’t hear, and writhing in pleasure at the sensations she was giving herself in this futon. The more I thought about it, the more dangerous brain chemicals were secreted. The soft fabric of the sweatpants was pushing up my erection, and my penis seemed even bigger than usual.

“Stupid Onii…”

Miyu’s eyes glared at my bulge. There was a sense of expansion in my crotch that I had never felt, even when I had a morning erection. If I didn’t masturbate now, even if I somehow managed to get through school, I would only be able to think about my sister masturbating during class.

“I can’t help it after seeing that.”

“What do you mean by ‘that’? It’s your little sister. It’s just your little sister’s familiar naked body. Why are you so excited?”

“I was fine just seeing you naked, but…”

“Gnu… So, your sister’s masturbation is that exciting to you…”

Of course it is. To be honest, even if we hadn’t had sex, I would have gotten an erection just from seeing her naked in this situation. I had seen Miyu’s naked body many times in the bath, but on a bed, a girl’s naked body looked even more lewd.

“Miyu doesn’t seem to be in the mood, I think.”

“I-If you want to cum, just cum. You said you were going to break away from me, but you stilll use me as a sexual aid. I won’t be responsible if you really can’t cum without me.”

Miyu tried to intimidate me while hiding her naked body. She said she would be responsible if I could never cum without her. Even if it was consensual, I wouldn’t hold back.

I took off my pants and stood next to Miyu’s bed. Miyu was watching me jerk off, even though she looked annoyed. No matter how many times I did it, the embarrassment never went away, but now, even the shame of being seen masturbating by my sister was becoming a source of excitement.

“Fuh… I think I’ll cum soon… Get your mouth closer…”

The pleasure given to my penis reached its peak, and I thrust my waist forward, but still, I couldn’t reach Miyu’s mouth. In order to ejaculate without dirtying the bed, I needed Miyu to get closer to me.

“Haa, haa… Miyu, I want to cum, so hurry up…”

“Umuu… You think your sister will just drink your semen like it’s nothing… You don’t know the trouble I go through…”

Miyu glared at me unhappily, but she still came closer to receive my ejaculation in her mouth. As she raised her face to the height of my waist, standing next to the bed, she naturally ended up in a crouching position. Since she had already been seen, Miyu seemed to have given up, and as the futon slipped off her body, her naked body was revealed.

I could feel my penis getting twice as big as I prepared to ejaculate. Not only Miyu’s bare breasts, but also her smooth, hairless pussy came into view, and there was no time left to wait a few seconds before ejaculating.

“O-On second thoughts, please wait and don’t cum yet, Onii-chan..”

“Huh… What… I mean, at this timing… I’m about to cum…”

“Just wait. Don’t rub it anymore.”

“Uhh… Kk…!”

I was stopped by Miyu, and I quickly gripped the base of my penis, barely holding back my ejaculation. Although Miyu was responsible for my erection, the right to ejaculate was always left to my sister, so this was the only option.

“W-What’s with you… suddenly?”

“Well, you see, drinking Onii-chan’s semen right before school, is kind of problematic for me.”

Miyu answered my question, twisting her naked body in a troubled manner, her tone suggesting that it was only half the truth.

“You’ve drunk it before going to school before, haven’t you?”

“It was fine at first, but things have changed recently.”

“What is…?”

What could be the reason for Miyu to be troubled by drinking my semen? If it was a play where I ejaculated on her naked body, I could understand wanting to avoid doing it before school.

Miyu was struggling to find an answer, her expression showing her frustration. This was a sign that she didn’t want me to pursue the matter further, so I decided to give up on finding out the reason for now. All I wanted to do was ejaculate.

“So, how do you want me to cum?”

“Can’t you just use a tissue? That’s what all the guys in the world do. You’re lucky to have your sister watch you cum. What’s your problem?”

“W-Well… I-If  you say that…”

Most of the sperm a man produces in his lifetime is ejaculated onto a tissue. There aren’t many relationships where a man’s everyday sexual desires are taken care of, like ours.

Even just having a cute girl watch me cum would be enough of a reward for me, and if Miyu was willing to do it, I should be satisfied with that.

“But I feel like it’s a waste to ejaculate on a tissue.”

“Your semen recovers in like, a day.”

Miyu was starting to make more sense. It seemed like I was out of luck. I should just be satisfied with the fact that I can use my sister’s naked body as a sexual aid.

“Well, I do have an alternative option, but…”

Just as I was about to give up, Miyu made a concession. This sister of mine puts up a lot of resistance, but her last stand is always weak. Rather, it seems that Miyu is unable to bend her sense of obligation and sentiment, once she has given permission. Also, Miyu has become more tolerant of sex lately, and even though she says it’s just an alternative, it’s quite a lewd proposal.

“Actually, it wasn’t a lie that the bra was too tight.”

“Didn’t you buy a new bra?”

Could it be that her breasts had grown so much in just one night? That would be very lewd… My sister’s breasts are getting too big, and it’s becoming difficult for me to control my sexual desire.

“Ignoring the stupid things you’re thinking, I’ll continue. This underwear set is an old one that I’ve been using for a while.”

Miyu picked up the orange bra and placed the cups on her breasts without putting on the straps. The meat on the sides was clearly not contained, and the straps were hanging down on both sides, making for an erotic picture.

“That’s the bra you usually wear, isn’t it? I thought you wore a night bra when you slept.”

“Don’t you know too much about your sister’s underwear?”

“Because I do the laundry!”

“Haa. I see.”

Miyu gave me a cold look and criticized me. What’s wrong with knowing that my sister wears a night bra? It’s not like I’m secretly keeping track of your menstrual cycle or anything.

“So, how does the fact that the bra is too tight lead to an alternative option? You don’t mean you’re going to let me do a titjob with that tight bra, do you?”

“I would never do such a perverted play even if it’s for my life.”

Of course not. Yamamoto-san agreed to a similar play with enthusiasm, but maybe it was because she was a pervert after all.

“Let me explain. This is an old piece of underwear that I can no longer wear. In other words, it’s garbage. In that sense, it’s not much different from the tissue you use to dispose of your semen.”

“Huh… What… do you mean…”

So, what Miyu is saying is that I can jerk off and cum on her panties, right? That’s too… too… perverted, isn’t it?

“But I’ll be getting your clothes dirty.”

“What are you talking about? I absolutely cannot allow you to dirty my clothes with your semen. As I said before, this is not clothing, but garbage. If you get excited by garbage, then I don’t mind if you use it to dispose of your semen.”

It’s still a pair of panties, no matter how you look at it. For Miyu, it seems that she can’t accept it unless she cuts it off coldly. Even though I feel guilty for stopping her from drinking my semen just before ejaculation, is there a sister in the world who would let her brother masturbate using her underwear?

“Was there a reason why you were sleeping in old underwear?”

“I didn’t want to admit that I now had such big breasts…”

This sister of mine was quite something. She had been a big breasted girl since she was young. If we were lined up in height order, she would be one of the first, but if there was a cup order, she would have been at the very back every year.

“Anyway, we don’t have much time, so I’m going to use it.”

I wrapped my penis in Miyu’s panties and started jerking off, while using my other hand to squeeze the cups of the bra together. The size of the cups was so big that they couldn’t be contained by a man’s hand, and the excitement was high, making it a perfect substitute for squeezing Miyu’s breasts.

Used panties usually have stains on the crotch, but for some reason, Miyu’s panties didn’t have any noticeable damage other than some fraying of the fabric. It’s possible that her pussy is so tight that urine or love juice doesn’t leak out easily. The absence of stains was proof that these were Miyu’s panties.

“Fuh… It’s embarrassing to be seen jerking off with my sister’s panties… but… it feels good…”

The cotton fabric that enveloped my penis, absorbing the pre-ejaculate that was dripping from my urethra, began to make a sticky sound, as if it were stirring my vagina.

“P-Please show a little more embarrassment.”

After the room was filled with a lewd atmosphere, Miyu finally seemed to realize her mistake. Letting her brother masturbate using her panties was nothing but a perverted act, and Miyu was becoming a part of it.

“Aaah… Haa… Miyu’s panties… her breasts… Nnuh, aaah… It’s exciting…”

I was so excited while masturbating with my sister’s underwear and being observed by her that I didn’t know what to do. The feeling of the fabric rubbing against my skin should have been painful, but the crotch, which was now soaked with pre-ejaculate, gave me the illusion that I was having sex with Miyu.

On the cup side of the bra, I enjoyed the size of Miyu’s breasts, and when I pressed my nose against the lining, the sweet, rich scent of Miyu’s nipples and sweat, which had rubbed off, spread into the depths of my nasal cavity.

“Fuh, suh, suuuh… Aaah… Miyu’s scent, haa, haah… It’s dangerous, I’m about to cum…”

“Onii-chan, um, that’s… really…”

“Haa… Haaah… I’m cumming, I’m about to cum…!”

“Uu… on second thoughts, no… Don’t cum on my panties, Onii-chan…”

It seemed that Miyu felt more shame than she had imagined, when she actually saw me masturbating with her underwear. However, Miyu was already holding back my ejaculation. This was the second time, and it wouldn’t be allowed. Miyu also knew this, so she didn’t try to stop me too strongly.

“Miyu… Miyu…!! I’m cumming, I’m about to cum, watch me…”!! Haa, nguh… Nnahaa, aaaah, aaaah!!”

Dbyurur, byurur, byukbyuk, byu, byu, byu—!!

The large amount of semen I ejaculated was absorbed by the crotch part, and a slightly yellowish stain spread. This time, the stain became proof that Miyu’s underwear had been soiled by a man.

“Guh… U, fuh… It’s still coming out…”

My excessive excitement made it impossible to stop ejaculating, and the panties alone couldn’t contain the semen, so I was able to finish ejaculating without dirtying Miyu’s room, by using the bra as a receptacle.

In the quiet room after I had ejaculated, Miyu, with slightly moist and bloodshot eyes, ordered me to “throw it away when you’re done.” Miyu only saw it as garbage, so I thought about keeping it, but since Miyu wouldn’t allow it, I decided to quietly throw it in the trash. I couldn’t even think about reusing my underwear, which was covered in my semen.

“That was the most pleasurable masturbation I’ve ever had.”

“Please understand what you’ve done with your sister’s panties. You’re taking advantage of your sister, who is in a state of confusion after being caught masturbating at night…”

It was meant to be a comment that showed respect for Miyu, but it seems to have had the opposite effect. Although Miyu seemed to be responding calmly, even though she had been caught masturbating in the middle of the night, her mind was apparently filled with anxiety and shame. As for whether it was garbage or panties in the end, I couldn’t tell.

After I had finished ejaculating, and Miyu had finished her role as a sexual aid, she first pulled her pajamas over her futon, putting them on without a bra. The shape of her breasts was visible through the fabric of the pajamas, making it even more erotic. Even though I had just ejaculated a large amount, I was getting aroused again.

Miyu seemed to sense my rising sexual desire, and she looked at me suspiciously from under the futon.

“Umm… Onii-chan, do you have no sense of guilt about getting excited over your real sister?”

“Huh…?”

It was a question that was far too late now that we’re at this stage.

Of course, I did feel guilty. I also felt a sense of sin for doing something I shouldn’t be doing. But I thought it was okay because Miyu was allowing it.

“What about you? Even the first time, but don’t you feel disgusted watching me masturbate?”

“Umm. Not really…”

Then aren’t you the same as me?

“Well, actually, it’s a little different.”

Miyu put on her pajama bottoms while still in her underwear.

“I have a lot of thoughts, but I don’t feel anything.”

“I see?”

“So, I do think it’s disgusting. Very much so.”

“Seriously…?”

I couldn’t tell the difference between the former and the latter, but Miyu did feel disgusted. That’s what a normal girl would feel.

“Onii-chan, can I tell you something?”

Miyu put on her school cardigan, covering up the outline of her breasts that was visible through her pajamas, and stood in front of me.

“Anyone would feel disgusted at someone who got excited and ejaculated over their own little sister.”

It was like a teacher admonishing a student.

It’s a given, isn’t it?

Why don’t I have that feeling though?

“Onii-chan, you really have no resistance to getting excited over your little sister’s naked body.”

“Yes. I’m sorry.”

“Why don’t you worry a little, too?”

“I’ll keep that in mind…”

I couldn’t raise my head, which was lowered. I didn’t really understand what I was supposed to change as a conclusion, but I should have worried and reflected more about my lust for my relative.

Even though she gets so angry, why does Miyu drink my semen? It’s probably better not to ask her now. It’s probably just a kind-hearted sister showing mercy.

As I was about to leave the room, I put my hand on the doorknob, and Miyu put her hand on the closet. I opened the door, and as I sensed that Miyu, who was in my field of vision, wasn’t moving at all, I looked over there for some reason.

“What do you intend to look at? I’m naked under my pajamas.”

“S-Sorry…”

I quickly left the room after being warned by Miyu. I had already seen her naked in the bath and during today’s masturbation, but it seemed that this was a different story.

Also, Miyu had said that if I looked inside her closet, she would cut off all ties with me. I predicted that it was filled with cosplay costumes, and I wasn’t allowed to inspect them yet.

Someday, I want to send Suzuhara and the others a two-shot photo, saying, “I made friends with a super cute cosplayer!” Regardless of my wishes, I hope Miyu continues her hobby, even though she’s already an adult.

It would cost a lot of money to do it seriously. In order for me to support Miyu’s hobby, I need an income. To do that, I need to go to a good university and get a job that pays well.

“I… have to study hard.”

With summer break just around the corner, I was filled with a very impure motivation.