How Using My Oppai Skill to Enlarge My Sister’s Breasts Led to Building a Harem - Chapter 3

Chapter 3

“Satsuki~ You got a sex friend, huh?”

“Yup, check this out.”

“Whoa! That’s wild lol!”

I showed a photo on my phone to the group of kinda slutty girls in my class. The image was of me, eyes blurred out, sucking a massive cock while throwing up a peace sign.

The cock in the photo? Obviously, it’s Ai’s brother’s.

Even to girls who sleep around for fun or profit, Onii-san’s cock was apparently a serious biggie. Thanks to that, I’d climbed to the top of the class’s social hierarchy, and my virgin complex was completely gone.

“Gotta go with an older, mature guy for sex, right~?”

“Ugh, Satsuki, you’re so lucky~ Share that huge cock with us!”

“Nope~”

“Tch, where’s a good guy like that at~?”

One of the girls, her uniform modded to show off all kinds of skin, wandered off.

(Ugh… all this talk’s got me horny again.)

I scrolled through the messaging app on my phone, checking when I could see Onii-san next. Maybe I’ll send him another oppai pic, I thought, half-listening to summer remedial classes.

(Forget studying, I just wanna have sex…)

I was totally addicted to sex.

※

Ai had plans to hang out with friends today, so I had a free day. When I mentioned being free to Satsuki-chan, I got a message back.

“Then come to my place today! Let’s have tons of sex♡”

Along with it came a naughty photo.

The image showed a gyaru-style beauty with a radiant smile. She’s Ai’s classmate, once self-conscious about her small chest, but now sporting gorgeous, full breasts. I knew it was wrong, but my groin stirred with thick, molten desire.

(Ugh, I’m such a cheating scumbag…)

…

I ended up at Satsuki-chan’s fancy apartment, just as she asked.

“I’m here.”

“Wait a sec! Be right there!”

Right after our chat, Satsuki-chan appeared.

“Sorry to keep you waiting, come in!”

“Uh, thanks for having me…”

It’s my first time in a girl’s house. I was a bit nervous.

“Satsuki~ You brought your boyfriend?”

A stunning woman appeared as I stepped inside.

“Hey, Mama, not a boyfriend—a sex friend.”

“Hmm~ Well, have fun. Mama’s sleeping till my night job.”

Not her sister, but her mom. Apparently, Satsuki-chan’s from a single-mother household, and her mom works nightlife, so she’s pretty chill about this kind of thing.

“Onii-san, my room’s this way.”

“R-Right.”

Her room was spotless, perfectly organized. The apartment itself screamed high-class, like they lived a pretty posh life.

“Here, take off your clothes♪”

Satsuki-chan started stripping, and I followed, both of us stark naked, gazing at each other’s bodies.

(She’s so cute. A different kind of beauty from Ai.)

Her translucent white skin, silky blonde-dyed hair, E-cup-ish gorgeous breasts, and perfectly proportioned figure. We’d hooked up plenty of times, but she’s stunning every time.

“Onii-san, we can do it raw today♪”

“Huh?”

“Mama gave me birth control pills, so creampies are okay!”

She sat on the bedside, spreading her legs to show off her pretty pussy, kupaa♡, wide open.

“Raw sex is okay?”

“I took the pill, so it’s all good♪”

Satsuki-chan grinned, totally unfazed. Her attitude got me completely in the mood.

“Satsuki-chan!”

“Ahn♡ Hurry and put it in~”

I pushed her down on the bed, pressing my cock’s tip against her pussy, dripping with slick aieki.

“Nnfuu♡ It’s going in…♡”

“Kuaa! So good!!”

The only time I’d done it raw was my first time with Ai. Back then, as a virgin, I was too overwhelmed to really enjoy it. But now, after tons of condom sex, I could feel the difference clearly.

“It’s gripping my cock so tight…”

“Nfufu~ Raw really lets me feel your cock’s shape, so good.”

“Yeah, your pussy’s sucking me in… incredible!”

Pachun♡ Pachun♡ Pachun♡ Pachun♡

“Nhaa♡ So good, Onii-san♡ Thrust harder~”

“Satsuki… chan, uaa! Haa haa haa!”

“Hiii♡ Your huge cock’s pounding me so deep♡ Hiii!”

I was completely lost in her tight, raw pussy. I could feel every fold of her walls, something condoms dulled.

“Ahn♡ Your head’s rubbing my pussy so much♡”

“Satsuki-chan, gonna rub your oppai.”

I reached for her trembling oppai, kneading them guniguni. I pounded her pussy, rubbed her breasts, and sucked on her delicate lips, drinking her saliva.

“Naa, juu, chupa♡ jururu♡”

Paan♡ Paan♡ Paan♡ Paan♡

Our sex got wilder, the sound of flesh echoing loud enough to reach outside.

“Ahaa♡ Amazing, amazing! Raw sex feels so good♡♡♡”

“Satsuki-chan! I can’t hold back anymore!”

“Come inside, Onii-san! Shoot your cum deep in my pussy♡”

Her begging for a creampie sent a thrill through me like nothing else. The sweet temptation of raw sex drove me insane.

“Satsuki! I’m gonna unload my cum!”

“Fill my deepest spot with your semen♡”

“Kuaaaa!”

I slammed into her pussy’s depths, zudon, and unleashed a flood of cum from my balls.

Dopyu♡ Byurubyururu♡

“Ohhh♡ It’s coming… hot cum shooting dopyudopyu♡…”

“Kuh… it’s milking me…”

Satsuki-chan’s pussy squeezed me tight, bikubiku, wringing out every drop as she spasmed. I trembled, savoring my first creampie, lost in pleasure until the waves finally receded. Then she spoke.

“Haaa… raw sex feels this good…”

“Second time for me, but this might be the best yet.”

“Hmm… not your first, huh? But I’m glad it was the best♪”

Pleased, Satsuki-chan begged for more, tempting my cock. Naturally, I couldn’t resist, and we went at it raw again and again.

…

Paan♡ Paan♡ Paan♡ Paan♡

“Hau! Satsuki! Satsuki!”

“Nnhiii♡ So good♡ Your cock feels amazing♡”

We lost track of how many times we fucked raw. Right now, I was on top, pistoning into her pussy like I was breeding her.

“Gonna come, Satsuki!”

“Aah! I’m coming, coming~~~♡♡♡”

The bed creaked, gishigishi! Ignoring it, I poured cum deep into her pussy, devouring the pleasure.

Just then—

“Hey, you two! How many hours are you gonna screw?!”

Satsuki-chan’s mom stormed in, fed up with the noise.

…

Satsuki-chan’s mom—Mizuki-san, apparently—had been trying to sleep after her night job. But our monkey-like sex next door kept her awake.

The fault was entirely ours.

“Sorry, Mizuki-san.”

“Sorry, Mama…”

“…Ugh, fine. I interrupted you guys too.”

Mizuki-san didn’t seem genuinely mad. Probably just snapped from lack of sleep.

“But, wow…”

Her seductive, gorgeous face turned to my body.

“You’ve got some nice equipment, boyfriend-kun♪”

Her smile was like a black widow eyeing prey.

“Hey, Mama, Onii-san’s mine.”

“Oh, he’s just a sex friend, right? Then I can have a little taste♪”

They started arguing, ignoring me completely. I froze, unsure what to do.

“Hey, I’ll pay you—wanna sleep with an older lady?”

“Mama!”

“Uh… Mizuki-san, you don’t look like an older lady.”

“See? Told ya♪ I’m the top girl at my job.”

“Ugh, Mama!”

Mizuki-san could pass for her twenties, but given Satsuki-chan’s age, she’s probably early thirties. Her flawless skin showed serious care.

“So, wanna do it?”

“No need for money… but could you share some of those birth control pills?”

“Ohh, that’s your angle? They’re not supposed to be shared, but… special exception.”

“Thanks!”

With that, Mizuki-san slipped the straps of her thin negligee off her shoulders, letting it drop to the floor, suton.

“Not bad, right?”

“Y-Yes, you’re stunning.”

Her body was mature—soft fat on her stomach, hips, and butt. The only flaw? Her breasts, symbols of womanhood, sagged slightly. But that just added to her charm.

“Fufu♪ You’re getting hard. Young guys are the best~”

She pushed me onto the bed, straddled me, and guided my cock to her pussy’s entrance.

“Here we go~♪”

“Khaa… ahh!”

Her pussy swallowed my tip, nupupu. Her labia, probably well-used, were large and lewdly shaped, but meticulously cared for—no darkening, with neatly trimmed hair.

“I don’t let clients go raw, y’know? Here, here!”

Pachun♡ Pachun♡ Pachun♡ Pachun♡

Riding me cowgirl-style, Mizuki-san bounced, her pussy squeezing my cock gently, kyukkyu♡. She rocked back and forth, stimulating me irregularly from base to tip.

(Insane technique… or is this what they call a pro?)

Against her masterful control, all I could do was endure the pleasure flooding from my cock.

“Fufu♡ So cute… such a huge cock, but you’re still green, huh!”

“Ugh, aaah…!”

She pinched my nipples, gyu, slamming her hips down, pachin pachin, like she was ravishing me.

“Fuh, fuh, fuh! Nnhaaan♡ A young guy after so long, so good♡”

Mizuki-san used my body like a toy, enjoying herself. Despite the humiliation, the relentless pleasure made my hips tremble.

Then I noticed her breasts, bouncing wildly, burunburun.

(All that movement’s making them sag, isn’t it?)

Instinctively, my hands reached for them.

“Here, here♪ Feel good in my pussy! Fuh, fuh… nnaaah♡”

“Let me make you feel good, Mizuki-san!”

I grabbed her oppai, gyunyu♡, roughly kneading to hit their pleasure nerves.

“Hey♡ Don’t rub my oppai like that!”

Ignoring her, I squeezed their incredible softness, milking from the base and pressing her stiff nipples with my fingers.

“Nhooo♡ That’s bad… my oppai are buzzing♡”

“It’s your fault for having such lewd oppai, Mizuki-san… njuu!”

I sucked her hyper-sensitive nipples, rolling them with my tongue, making obscene sucking noises.

“Aahii♡ That’s too much! Ohhh♡”

My hands kneaded her soft breast flesh, munimuni, hitting the perfect spots to send pleasure deep.

Paan♡ Paan♡ Paan♡ Paan♡

I thrust upward with my rock-hard cock, adding to the onslaught.

“Nooo♡ That’ll drive me crazy♡”

“You’re so cute, Mizuki-san!”

“No… my daughter’s boyfriend’s gonna make me come!”

Panpan! Panpanpanpan!!

I slid my fingers to her nipples, pinching them hard, kyuu♡, just as she exhaled deeply to release the pleasure.

“Hahii!? Aa, haaa♡ Ohhh♡♡♡”

Caught off guard, Mizuki-san’s body jolted like it was shocked, her sultry, feminine moan spilling from her glossy lips.

“Ohhh♡ I’m coming… I can’t stop coming♡♡♡”

“Go for it! Let your pussy come too!”

Batchu♡ Batchu♡ Batchu♡ Batchu♡ Dochun♡

“Auuu♡ No more… I can’t…♡♡♡”

I released the pent-up urge to cum. Like a hose unplugged, semen surged from my balls, and I shot it deep into her pussy.

Byuru byuru♡ I ground my hips, guriguri, hitting her cervix, thrilled to creampie my sister’s classmate’s mom.

“Haahe♡ Your dekachin grinding is too much♡ Ahh…♡”

Completely broken, Mizuki-san collapsed onto my chest, half-rolling her eyes.

“You’re amazing, Mizuki-san… nju, jururu.”

“Ahh, seduced by such a young guy… nju♡ juzuzuzu♡”

We kissed passionately, like lovers, no roles or boundaries—just a man and a woman.

…

“Haaa, that was incredible♪ Boyfriend-kun.”

“Ugh, Mama, don’t screw him that hard in front of me!”

“But he was way better than I expected, so what could I do?”

Mizuki-san smiled at me. I suddenly felt shy, having gone wild with an older woman.

“And he’s not my boyfriend, he’s my sex friend! That’s rude to Onii-san, Mama.”

“Ugh, relationships don’t stick to labels like that~”

“…Maybe, but still.”

“Just get pregnant and make him take responsibility♪”

“What?! Mama!?”

Their crazy conversation made me stare at them. Mizuki-san kept smiling.

“Then he’d be my son-in-law.”

“…Isn’t that just you wanting to keep screwing him?”

“Ufufu♪”

I couldn’t tell if she was serious or joking, but her grin didn’t stop.

I broke out in a cold sweat, wondering if this mother-daughter duo was about to dictate my life.