My Little Sister Is the Best F*p Material

Volume 3 Chapter 10: A Daily Life with a Busty Little Sister

The next morning, as I stepped out of my room, I bumped into Miyu in the hallway.

“Good morning.”

“It’s you, Onii-chan. Good morning.”

Miyu looked at me with her adorable eyes, appearing as if nothing had changed. Although the punishment she gave to Yuka yesterday was extreme, Miyu had remained dry and unemotional throughout. It seemed she wasn’t dwelling on it. So, I thought it might be okay to ask about Yuka.

“Is Yuka okay?”

“She’s fine. She’ll probably be back to her usual self today.”

Miyu answered casually. Considering Yuka’s personality, it wasn’t surprising that she had recovered so quickly. Still, I couldn’t help but feel that the damage was too great for her to simply bounce back.

Perhaps sensing my concern, Miyu continued to explain.

“Between us, there’s an unspoken agreement that we won’t cross certain lines that are absolutely unforgivable. So, you don’t need to worry.”

“R-really? Then, I’m glad.”

According to Miyu, both Yuka posting the photos online and Miyu losing her virginity were things they knew would be safe, in a way. Of course, I couldn’t easily accept this, but hearing her explanation, my mind settled a little.

“Then, can I talk about something unrelated?”

“What is it?”

I calmed down and looked at Miyu’s pajamas. The smooth fabric revealed her body lines, and her breasts, which had grown rapidly in the past few months, were even more emphasized than usual.

“Aren’t your pajamas a bit too sexy?”

It was a straightforward opinion. With our parents already on their trip, I would be spending the entire summer vacation with my sexy pajama-clad sister. Although I intended to work on my “sister detachment,” when asked if I could keep my feet on the ground after my usual processing, I had to admit that I wasn’t so confident.

“Is it that sexy?”

Miyu looked at her own emphasized breasts again, appearing a little embarrassed. It was a cute reaction.

“Come to think of it, maybe it is. I bought these pajamas partly to stimulate your sexual desire.”

“Why would you make such a wasteful purchase…”

Well, for me, it wasn’t a waste at all. It was a bold move, considering the purpose was to accumulate my sexual desire so that I could have a five-round battle with Yuka.

“Onii-chan.”

Miyu looked down at my crotch. My penis had become erect as I looked at Miyu’s breasts.

“Why don’t you do something about that sexual desire of yours?”

I was being scolded for being able to get an erection again, even after ejaculating so much yesterday. This sister of mine didn’t seem to care that she was the one who had made my body like this. My semen had become thicker, and it was becoming more difficult for Miyu to drink it, yet she didn’t seem to realize that it was because of her that my potency had increased.

“I’m reflecting on it.”

Regardless of my sexual desire, having large breasts was a complex for Miyu. It was a physical concern that couldn’t be resolved with effort, so I thought it was best not to pay too much attention to Miyu’s breasts, especially since we saw each other every day.

With that in mind, I tried my best not to look at Miyu’s body. Of course, during breakfast, while getting ready in the bathroom, and even when Miyu changed into her uniform, I tried to keep her breasts out of my line of sight. Even after school, when she was wearing a T-shirt, I controlled myself, knowing that it was inappropriate to lust after the shape of her breasts that were visible through the fabric.

It was like trying to keep the surface of a pond still in my mind, and after two days, I was getting used to living like this.

And yet…

“Hey, Onii-chan.”

As I took a bath first, and then, when I came out of the bathroom, Miyu and I crossed paths in the kitchen to get some water. Miyu pulled on my clothes from behind and, unbelievably, hugged me around the waist.

“W-what’s going on?”

“That’s what I’d like to ask you.”

Miyu looked annoyed.

“It feels like you’re ignoring me, Onii-chan. Your little sister is a bit lonely.”

Her cute statement made me startled.

“Is something wrong?”

“Well, it’s more like… Miyu is self-conscious about her big breasts, so I thought it would be rude if I got sexually excited about them…”

“It’s okay, Onii-chan. We live in the same house anyway.”

According to Miyu, it was impossible for a man not to be aroused by big breasts, and she would rather I not try to keep them out of my sight. There was a caveat, though, which was that it only applied to me.

“Is that so? … I guess you’re right.”

“Yes yes.”(T/N: She said this in a cute way, “Desu desu”)

Perhaps I had been thinking foolishly. After all, I had used Miyu’s breasts as my “food” many times before, and now, to act like a saint was a bit strange. Maybe there was a part of me that felt guilty towards Yamamoto-san, which led to this behavior.

“Well then…”

“Yes?”

“Because I’ve been trying not to use Miyu as my ‘masturbation material’ for the past two days, I haven’t masturbated even one.”

“Okay, okay.”

Miyu quickly understood my desire, like a mature girlfriend. I sat on the sofa, which had become our usual spot for such activities, and Miyu sat in seiza in front of me.

“You know, Miyu, how far are you willing to go now?”

“Even if you ask me how far… My stance remains unchanged—I’m merely here to take care of your semen.”

“What about you breasts?”

“You mean, a titjob? What’s so good about it?”

Miyu lifted her breasts, which were protruding from her pajamas, from below and observed them curiously. Unlike the vagina or mouth, they didn’t have good lubrication, and they weren’t a place where one could skillfully stimulate like a handjob, so Miyu wondered if it would even feel good.

“Just seeing them being squeezed together is exciting.”

“Hmm. Like this?”

Miyu placed her soft, rounded breasts on my knee, and then, leaning forward, she pressed her breasts against my crotch. They had a weight beyond their appearance, and even with our clothes on, the softness of the accumulated fat in her breasts felt very real.

“Oh, oh… it feels good, this… it’s very exciting…”

“I can feel your penis getting hard through your clothes.”

Because I had been holding back, my penis became erect just from having her breasts pressed against it. This was something we both expected, so we exchanged glances, acknowledging this fact with a simple “I know” expression.

“You know, the other day, when you initiated physical contact with me, it was because of Yuka, right? You don’t really like being all touchy-feely, do you?”

As Miyu tried to press her breasts against my crotch while sitting on the sofa, she naturally ended up hugging me around the waist from the front. Although this was at my request, it could also be seen as Miyu initiating physical contact.

Besides, when she stopped me, Miyu had even hugged me from behind. If this wasn’t still part of the punishment, then these gestures of affection from Miyu seemed to contradict her previous statements.

Thinking this, I decided to confirm Miyu’s feelings, and she looked up at me for a while, then silently stood up and fit herself perfectly between my knees, seemingly unbothered by my erection.

“I seem to be okay with you, Onii-chan.”

Miyu turned around, gathered her long hair on the opposite shoulder, and then took my hand, guiding it around her waist. She claimed that just being in a crowded train made her feel sick, and she didn’t like being touched by her female classmates, even with Sachiko and Haruka, she would choose the right time and place. Yet, she was taking a brother who was sexually aroused by his sister, focusing his heat on her lower abdomen, and initiating physical contact with him.

“In this position, I could rub against you.”

If I hugged Miyu and rubbed my erect penis against her body, I could ejaculate without even taking off my pants.

“Even if I don’t feel disgusted by that act, I think we should limit our physical contact to that of siblings.”

“You’re right.”

I was impulsive and would quickly cross the line, but thanks to Miyu’s calmness, we were able to avoid crossing that line. Of course, even Miyu would probably refuse if we were to go too far.

“Then, can I do it until I cum in the previous position?”

“Since I initiated it, I can’t refuse, can I?”

Pressing her breasts against my crotch, even through our clothes, was not an appropriate distance for siblings. Still, since we had done it once before, I thought Miyu wouldn’t refuse me.

“Umm, well. By the way, you’ve been wanting my breasts a lot lately, but is it that time of the month for you?”

Miyu took the same position as before, roughly pressing her weight down on my erect penis with her breasts. Her slight movement forward and backward was erotic.

When asked if there was a time when boys wanted breasts, the answer was not a complete no. However, that wasn’t the case with recent events.

“It’s not really comparable, but Yamamoto-san’s breasts are really big.”

“Hee~”

Miyu narrowed her eyes. What was that reaction for?

“I asked her to do a titjob, and she said it was okay. Since that happened, I’ve been paying more attention to breasts.”

“I see. I wouldn’t do it, though.”

“I know.”

How one interprets this situation of having breasts pressed against one’s crotch depends on the person.

“How’s it going with Kanade-san?”

“I think there’s a good chance. Actually, I met her on Saturday, and we talked quite a bit. She even said we should talk more just the two of us.”

“You’re really trying, Onii-chan. Then, it seems you can also detach yourself from your sister.”

“Yeah. Yamamoto-san is also quite skilled in bed, so if we can make time during summer vacation, I might be able to get it done sooner than expected.”

Yamamoto-san didn’t seem to be in any club activities, and if she could free up some time from her part-time job or hanging out with friends, she should have some free time. Fortunately, I had also obtained her contact information, so the day when I could ejaculate without using Miyu as my “food” shouldn’t be too far off.

“So, as a sort of last memorial, can I do it while I’m naked?”

I placed my fingers on the waistband of my pants and asked for Miyu’s permission. I wanted to enjoy her pajama breasts with my penis exposed.

“Normally, I would refuse because I don’t want to get my new pajamas dirty, but I know you’ll ask me to let you do it anyway.”

Miyu complained, then wrapped her arms around my back and unfastened the hook of her bra. What… was she doing?

“Eh, is it okay to do it with your bare breasts?”

“I’ll just take off my bra. It’ll just be painful if the hard part rubs against it, right?”

“That’s true, but is it okay?”

“Well, as a memorial.”

Miyu mumbled her answer. She was so stubborn in strange places.

“Then, please do this for me.”

Leaning against the backrest of the sofa, I took off my pants and moved my waist forward, and Miyu placed her breasts, which felt like water balloons in her pajamas, on my crotch.

Despite reducing the number of clothes, the weight seemed to have increased even more. The softness of her breasts and the smoothness of the pajama fabric made the titjob possible without any lubrication.

“Should I move it for you?”

“Since it’s a once-in-a-lifetime experience for both of us…”

“It’s a real titjob now, right?”

“Umm… well… let’s call it a pajama job…”

“It’s a titjob.”

“I’m sorry, I want you to do a titjob on me, Miyu.”

I admitted my desire, and Miyu sighed deeply, “Haa…” Sacrificing such an important piece of clothing was already a big deal, and if she were to do a titjob herself, it would probably exceed her capacity for humiliation.

“I’ll move it for you, but just to be clear, this is not a titjob. In the future, if you talk to me as if I have experience with titjobs, I’ll be troubled.”

No matter how you looked at it, the act that would follow was undoubtedly a titjob, but it was important that Miyu didn’t acknowledge it, just like she didn’t acknowledge handjobs.

“Feel good and cum, okay?”

Miyu lifted both breasts with her hands and began to stimulate my penis. Perhaps because she didn’t want her breasts to move too much and draw attention, Miyu moved in sync with her breasts, and her hands lacked the usual delicacy. Still, the warmth of her breasts felt very real in this play, and ejaculating wasn’t too difficult.

Additionally, I had more than just that to get off to. Miyu’s breasts, with her pajamas on and no bra, had visible nipples. Even that alone was so erotic that I could have ejaculated, and it seemed that Miyu enjoyed the feeling of her nipples rubbing against my skin, as she let out hot breaths and took deeper breaths.

“Umm… fuu… haa, fuu…”

Miyu slowly moved her breasts up and down.

There was a hint of regret in her swimming eyes.

“Does it feel weird when my nipples rub against it?”

“N-no, not really.”

“I see. Then, that’s good.”

Perhaps it was embarrassing for Miyu to be thought of as feeling anything, so she maintained a blank expression while doing the titjob. Still, she couldn’t hide her body’s reaction, and the shape of Miyu’s nipples, visible through her pajamas, gradually became more defined.

I could touch Miyu’s nipples now, and if I rubbed them with my fingers, they might be quite sensitive. If I did that, Miyu would moan in an erotic voice, and then, she would get really angry.

“I think I’m about to cum, so can you move a little faster?”

“Umm… yeah…”

Miyu was still trying to keep a neutral expression. She was pretending not to feel anything with her nipples, so she couldn’t refuse my request to do it more vigorously.

“Fuu… umm… ummm… fuu…”

The movement of her breasts became more intense, “tapun, tapun,” and Miyu was feeling the rubbing of her nipples against the pajamas, trying to hold back her erotic voice. It was just a very small voice, like a sigh, but it was the first time I had heard Miyu’s sensual voice, and I was more excited than ever.

“Uu… your penis… it’s twitching so much… are you about to cum…?”

“If you rub it a little more, the switch will turn on. Can you drink it in that position?”

“I can’t drink it directly… so, on my stomach. Then, I’ll lick it later…”

Miyu knew that I had realized she was feeling something with her nipples rubbing against the fabric, but she couldn’t say it out loud, so she tried to maintain a straight face while rubbing my penis with the bulge of her pajamas. I loved Miyu for that, and I was so close to ejaculating that I took off the clothes I was wearing on my upper body, leaving me completely naked.

“Uu… it feels like we’re doing something really erotic…”

A naked brother, and his sister, with no bra, rubbing her chest against him. No matter what Miyu said, this was a titjob with only a thin fabric between us, and it was undoubtedly sex between siblings.

The movement of the pudding-like breasts, visible through the fabric, made me realize once again that I was getting a titjob that was almost as good as the real thing, and my penis, trapped between my sister’s breasts, was urging me to ejaculate quickly.

“Ahh… the switch is on…!! Miyu, is it okay if I move it myself…?!”

“Eh? Oh, yeah.”

Miyu gave a dazed reply. Perhaps she was so focused on not feeling anything with her nipples that she didn’t even understand what I was asking. Still, I didn’t care, and I moved Miyu’s hand out of the way, taking over and grabbing her breasts, rubbing my penis against them in sync with my waist movements.

“Umm… uunn… o-onii-chan… I… something… fuahh, aah…”

The friction of the fabric became more intense, and Miyu’s nipples, stimulated by the rubbing, seemed to be quite sensitive, but my hand, on the verge of ejaculation, didn’t stop.

I grabbed Miyu’s ample breasts with my whole hand and shook them up and down, and even though they felt as heavy as basketballs, I used that weight to rub the surface of my penis. The undulating flesh massaged my penis, and the increased blood flow made it even bigger.

“Fuuu… aah, it feels so good… it’s so soft…!!”

“Umm, uunn… fuu, haa… umm… aah, Onii-chan, no… it feels weird…! Fuwa… aah… ummm… uunnn…!!”

“Aaaah, I’m gonna cum… I’m gonna cum… Miyu, I’m cumming, I’m cumming… aaaah…”

Buru, buru, buru, buru, bu, bu, bu, bu, bu, buu…!!

White liquid spurted out from the tip of my penis, flying into the air and falling onto my abdomen. Neither of us had done any intense exercise, yet we were both panting. Miyu, in particular, was blushing up to her ears, looking down, her knees pressed together, and she said nothing.

“Miyu, can you lick this off?”

When I asked Miyu to take care of my semen, she raised her face, which I had never seen so melted, and without even taking a breath, she opened her mouth.

“Faa… haa… yes…”

Miyu, with a vacant expression, leaned forward and began to lick the semen that had attached to my stomach. She sucked up a lump with a “chup” sound, swallowed it, and then licked another spot.

(Umm… what is this… Miyu… so erotic…)

Being licked felt so good that my erection didn’t go down, even after ejaculating. And the more I let Miyu lick my semen, the more she became obsessed with kissing my body. It even seemed like she was enjoying the act itself as an erotic experience.

“Uu… aaah…”

Miyu licked my body without even considering how I felt, and eventually, she stared blankly at my stomach, now clean of semen. Then, as if seeking the last drop of semen, she brought her mouth close to the tip of my penis and sucked it out with a light “chu…” like a bird’s kiss.

“—!?!”

I moaned in surprise at the sudden pleasure, and at the same time, Miyu, who had come to her senses, screamed.

“A… this… it just happened to touch my mouth…!!”

Miyu stood up as if she had been startled, and she couldn’t hide her confusion as she frantically asserted her innocence, saying, “It was not a cleanup! At least, not by my will…”

I had my penis erect, even though it was unintentional, and Miyu had witnessed it. She pushed a tissue box towards me and, hiding her nipples, which were visible through her pajamas, with her arms, she kept her distance.

“I won’t do it today. You take care of the rest yourself.”

Miyu said that and, without waiting for my reply, she quickly left the living room. I couldn’t understand how this had happened. Before I could even consult Yamamoto-san, my erotic relationship with Miyu had progressed so much.

(Today’s wasn’t a titjob or a blowjob, so it’s okay, right…?)

Using the mysterious criteria that Miyu had influenced me with, I tried to make excuses to myself and regain my composure, but all I could do was stare at Yamamoto-san’s account on the messaging app with my flaccid penis hanging down.