How Using My Oppai Skill to Enlarge My Sister’s Breasts Led to Building a Harem - Chapter 10

Chapter 10

My clinic is running smoothly.

Besides my regular massages, I perform special massages for patients referred by Ayaka-san, all by appointment only.

“Thank you, sensei. I’m completely better thanks to you.”

“No, no, I’m just glad you’re healthy again.”

The elderly lady bowing in gratitude had a malignant tumor, which I successfully treated.

I’ll treat any woman’s breasts—age doesn’t matter. There’s no hierarchy when it comes to oppai.

“The treatment fee is really just the massage cost?”

“Yes, 30 minutes today, so 1,000 yen.”

Honestly, it’s dirt cheap even for a massage. But money isn’t my goal.

(If these hands are a gift from God, using them for profit feels wrong.)

As long as I cover the clinic’s cheap rent and utilities, I’m good.

“Good work, sensei.”

“Oh, thanks as always, Ayaka-san.”

Ayaka-san often helps out, and our secret relationship continues, aiding me in many ways.

※

At the same time, my relationship with Yukino persists—no, it’s gotten even more intense.

“Nn♡ Pound my ass harder… zubozubo♡”

“Yukino, break time’s almost over.”

“Then fuck me harder♪”

We’ve started having sex during short breaks in the school’s rarely used girls’ bathroom. Besides regular sex, Yukino’s hooked on anal, tempting me constantly.

“I’m gonna thrust hard, so keep your voice down, okay?”

“U-Un♡”

Paan! Pampan♡ Pan Pan Paan♡

“Nnnu~~~♡ Fu♡ Nfu… au♡”

Panicked by the time, I used my full strength to slam my cock into Yukino’s ass.

Bachin♡ Bachin♡ Bachin♡

“Ohhh♡ My ass is breaking~~~!”

Her anal tightness told me she was close to climax.

(Let’s try that…)

“Here, I’ll make you come! Come now!”

Using rough words, I grabbed her ass, imagining it as oppai while kneading.

“Haan♡ Why… my ass is being rubbed, but my breasts are burning…♡”

Rubbing countless breasts, I realized all nerves are connected. If so, I could stimulate pleasure from anywhere with my hands—and this was it.

“Here we go!”

Pachin! Munyu♡ Guniii♡ Pampan♡ Pan Pan Paan♡

“Ohh♡ No…! My ass to my breasts are tingling…♡”

“Yukino! Your voice is too loud…!”

I quickly covered her mouth.

“Kuhhooo♡ Nnnu (My ass-pussy’s coming… coming, coming~~~♡ Ah…♡♡♡)”

As I muffled her, Yukino climaxed anally in the school bathroom, letting out a lewd moan into my hand.

She convulsed, eyes rolling back, accepting my rectal cumshot.

(I overdid it…)

Yukino’s insatiable lust keeps escalating. No one’s caught us yet, but we’ll get exposed eventually.

“Gotta do something.”

But my sense of crisis came too late.

※

The next morning, I found a letter in my desk.

(What’s this…?)

“To the pervert having sex in the school bathroom♪ If you don’t want this exposed, stay in the classroom alone after school.”

(Blackmail…?)

The quirky, rounded handwriting seemed like a girl’s. Knowing someone—anyone—had my secret terrified me.

“What’s wrong?”

“Nothing, Yukino…”

It said “alone,” so I couldn’t tell her. I spent the day feeling a cold chill down my spine.

…

After school, I pretended to leave, then returned to the empty classroom to meet the blackmailer.

“Sorry to keep you waiting♪ You came alone, huh?”

“You’re…!”

I recognized her—my classmate, of course.

(The girl who talked to me after summer break.)

Her name was— “Hidaka Riria♪ Can’t even remember your classmate’s name?” —right, Hidaka-san.

“Okay, Hidaka-san, why’d you call me?”

“Nishishi♪ Guess why?”

“…Money?”

“Hmm, that’d be nice, but… I want something else.”

Something other than money… do I even have something she’d want?

“I don’t get it. What?”

“I get all excited seeing things others treasure♪”

“Something I treasure?”

“Haha, no. I want your body♪”

My body? Why me? Then I remembered Yukino’s words:

“The girls in class… they’re after you.”

Right, she said girls were targeting me because I’m the model’s boyfriend.

“Why me?”

“‘Cause your cock’s huge, right?”

“H-Hey, not here…”

“I don’t have a boyfriend right now… and I’m so horny♪”

Hidaka-san gave me a lustful look, lifting her skirt.

“!?”

“See, you reacted♪ Guys only think about sex, so no need for extra talk, right?”

Her words belittled all men, but I couldn’t tear my eyes from her beautiful thighs and flashy panties, unbefitting a high schooler.

“Haha, you wanna fuck, don’t you?”

“N-No, that’s…”

“Liar. Your cock’s hard♪”

She reached for my crotch.

As she said, my cock was fully erect, straining against my pants.

“Wow♪ It’s really big~ Looks like it’ll feel better than my last boyfriend~”

“Ku… damn…”

I knew I was lustful, but I was shocked my cock stayed hard even under threat.

“C’mon, you can’t go home like that, right? Let’s take care of it.”

“Fine…”

Giving up resistance, I used my secret key to sneak into the old library storage room.

…

“Wow, this place exists? And you still fucked in the bathroom? How horny are you, haha!”

I stayed silent, unable to retort.

“Whatever, let’s fuck. But if you don’t satisfy me, I’ll spread proof you and Yukino were screwing in the bathroom.”

“What!? You’re kidding…?”

Hidaka-san grinned lewdly, taunting me.

“If you don’t want that, show me your cock.”

“Got it…”

Shamelessly, she stripped, tossing aside the black lace panties I’d seen, exposing her pussy.

“Your nipples… pierced?”

“Yup~ Cute, right?”

Her nipples had horizontal piercings. Her breasts were beautiful, with lovely color, without needing that… but I, an outsider, had no right to judge.

“Yeah, sure…”

“C’mon, strip. Hurry up with that cock.”

With her holding evidence, I couldn’t resist. Wanting to get it over with, I shed my clothes.

“Ohh~♡ Big, brutal, perfect cock. No wonder Sasahara Satsuki brags~”

“You seem… experienced, Hidaka-san?”

“Hmm~? Had lots of boyfriends, but they don’t last.”

“Really?”

“‘Cause if a guy can’t satisfy me, what’s the point, right~?”

Grabbing my cock, Riria stroked it, shikoshiko♡, with practiced skill.

“Ku… Hidaka-san…”

“Call me Riria.”

“Kua… R-Riria…”

“Haha, I’m good, right? Shikoshiko~♪”

Riria gripped my cock with perfect pressure, caressing from base to glans with her slender, white fingers.

“Nice~♪ Thick, long, veiny, lewd cock♪ I’ll pamper the head too♡”

She wrapped her soft palm around the glans, squeezing, guniguni.

“Gu… haa…!”

“Nishishi, it’s working♪ Don’t you wanna stick it in my pussy now?”

“Ah… uaa…”

“With a cock this lewd, you can’t hold back, can you~?”

I knew I shouldn’t give in, but my lust swelled, shutting down my brain.

“C’mon, follow your instincts and ram it in my pussy♪”

Whispering in my ear, she trapped my cock between her soft thighs. Feeling her feminine flesh, my rationality collapsed.

…

Paan!! Paan! Paan! Paan!

“Ah♡ Ah♡ Aaa♡ My pussy’s breaking~~~♡”

“Gonna come again! Take it in your pussy… ugh…!”

I unleashed my tenth cumshot into Riria’s pussy. Provoked endlessly, my cock stood raging, never satisfied no matter how many times I came.

Paan! Paan! Paan! Paan!

“Ah♡ Ah♡ Aaa♡ Please, mercy…♡”

“Still more to go!”

My limits gone, I became a beast devouring her soft flesh. My new finger technique, perfect for a lewd girl like Riria, let me ravage her by stimulating pleasure from any part.

“At least… ah♡ Let me rest…”

Paan! Paan! Paan! Gunyu♡ Guniii♡

“Ahaan♡ Don’t rub my breasts♡ Ugh, I’m… coming~~~!! …Hau♡♡♡”

“Your favorite big cock. Enjoy it.”

“No more… my hips won’t move…”

“Fine.”

Grabbing Riria’s ass, I lifted her with brute strength and dropped her onto a nearby desk.

“Au! Hey, what’re— Ohhh~~~♡♡♡”

“Hn! Hn! Hn!”

Zupan! Zuchu♡ Zuchu♡ Zuchu♡

Holding her shoulders firmly on the desk, I slammed my hips.

“Why… won’t you let me rest♡”

“This way, you don’t need to move your hips!”

“That’s not it…♡”

I knew, but I had no intention of letting her rest. Leaving her with evidence was too dangerous. So, I’d fuck her until her rationality broke, making her submit.

“Hn! How’s that, Riria!!”

“Ogo♡ Help…♡ No more coming…♡ Ah… ah, ahh~~~♡♡♡”

Riria convulsed wildly, climaxing repeatedly.

Dochu♡ Dochu♡ Dochu♡ Dochun♡… Byurubyururu♡

“Ohh~♡ This is crazy…♡ Aaa…♡♡♡”

“Passed out? We’ll go again when you wake.”

I pulled my cock from her cum-drenched pussy, and thick semen gushed out, goboo♡, forming a white puddle.

…

“Riria, how was sex with me?”

“Haha♡ Amazing~♡ Let’s do it again~?”

“That’s up to you. Now, as promised, delete that evidence.”

I took her phone, unlocking it with facial recognition.

“Here… yeah, it’s me and Yukino.”

The video showed us entering the girls’ bathroom.

“Oi, Riria. This the only video?”

“Yup~♡”

“Lie, and we’ll never fuck again.”

“It’s true~”

Trusting her for now, I deleted the video.

“C’mon, let’s go home.”

“Can’t stand~”

Her legs trembled like a newborn fawn, cum dripping from her pussy. It was kinda funny—

“If you betray me… I’ll leak this video.”

I filmed her pathetic state.

“That’s the worst… don’t do it!”

“Haha, kidding.”

Thus, we formed a strange friendship.

And with two school fuckbuddies, my lower half grew even wilder.