The Story of How Producing My Timid Older Sister Developed My Sexual Preferences

Chapter 004: Tanned Flat Chest Has Sensitive Nipples ☆

“I’m putting it in. Spread your legs.”

She looked at me with moist eyes and gave a small nod. She moved her hands, which had been clenched tightly near her mouth, behind her knees and pulled them back, spreading herself into a wide M-shaped position.

The transparent, thick fluid pooled at her entrance was forming strings and looked like it was about to spill onto the sheets. What a waste. I scooped it up with my glans and smeared it over her puffy labia. Even through the condom, I could feel the scorching heat of her mucous membrane.

… I can’t hold back anymore.

With a tight michi michi michi sound, the black condom dug into her small hole and pushed deeper and deeper inside.

“Ugh!? Ah! Ah! Aaaaaahhhhh!!!!!”

The long-awaited pleasure made me leak a groan, but it was completely drowned out by Shiori’s loud moan.

The moment I reached her deepest point, I slowly pulled back, scraping the ceiling with my rock-hard cock.

“Ah! No! I already came! Ah… ahh… nnn…”

“No, I just put it in.”

“It’s too big! My belly is getting crushed…”

“…Then shall I crush your womb (belly)?”

I brushed her hands away, grabbed her sweaty, slippery thighs, spread them into a V-shape, and leaned forward, putting my weight on her.

At first, I moved slowly, thrusting in and out.

“Aaaaaaaaaaaaaaaaaah!!!!!! Aah! Aaah! Aaaahhh!!”

Gradually I started slamming my hips harder, making loud pachu pachu sounds. Every time I hit her depths, her voice cracked. The way her two-toned thigh muscles jiggled lewdly was incredibly erotic.

I kept pistoning at a steady rhythm, forcefully loosening her tight, hard vaginal walls. White love juices overflowed so much it looked like I had already cum inside her.

Pachu pachu pachu pachu pachu

“Ugh… ughh… aaahh! Ah! Aaaaahhh—!”

Sweat poured from her tanned skin and collected in the grooves of her abs, forming little rivers. If you looked closely, you could see my cock bulging out her lower belly every time I thrust deep. This was only visible because she had so little body fat.

Pachu pachu pachu pachu pachu

“Shiori! You’re so fucking erotic! Keep going!”

“It’s too much!! I’ve been cumming the whole time!!!”

“Not yet! You can take more!”

“Uuuu—! I can’t—! I’m cumming! I’m cumming! Aaaaaaaaaaaaaaaaaah!!!!!!!”

Suddenly her legs thrashed wildly and broke free from my grip. I’m confident in my arm strength, but there’s no way I can win against her leg power. Her powerful legs wrapped around behind my back and locked my waist tightly so I couldn’t piston harder. My cock ground firmly against her cervix.

“Nngoh!!!?”

Even though she was the one holding me, an unexpected deep thrust hit her perfectly and she let out a vulgar cry. Psssh! A powerful squirt hit my lower abdomen. …Just as I thought, Shiori is a total lightweight pussy.

“Aren’t you supposed to defeat the evil cock!?”

“Haa—! Haa—! Haa—! I’m sowwy… I surrender!”

“What was that!?”

I slapped her tanned thigh with a loud smack.

“Nyah! I’m sowwy! I give up!!”

“Surrender accepted. However, the captured prisoner Shiori will now be interrogated.”

My sweat was bad, but she looked like she might suffer from dehydration. Her gray sporty cotton bra with “ck” on it was heavily darkened by sweat.

Still inserted inside her, I leaned over her and brought my face close. She was covering her eyes with her arm like a crying child. I roughly pulled her soaked bra upward, exposing her small breasts.

“Uuuu~ Nooo, not my boobs…”

“No can do. Losers have no right to refuse.”

Shiori is self-conscious about her small chest. I, on the other hand, love it. Big lumps of fat on her body would feel out of place…

The white skin that had been protected by her uniform from the sun contrasted beautifully with her tanned body. Her small areolas were a light color between pure white and tanned skin. Her nipples were also small, but — just like this — they showed surprising erection power. They had probably gotten hard in anticipation. What a cute girl.

She kept hiding her half-crying face. I whispered into her ear while placing my index finger and thumb on her right nipple.

“You invited me over today because you wanted to fuck, right?”

“Haa… haa… Yes.”

“Good. When was the last time you masturbated?”

“………… Before the test.”

I pinched her nipple hard and kept the pressure.

“Ngyiii!! Y-yesterday! I did it yesterday!!”

I loosened my grip. Her pussy squeezed me tightly.

“Why did you do it yesterday? When exactly?”

“Y-yes… Yesterday after karaoke, I wanted to do it with Teru but you went home… so I was lonely and did it alone when I got back…”

“…Cute.”

Squeeze.

“Nnaah!? Whyyy…”

“Even if you’re cute, sometimes you still get punished.”

“I don’t like this anymore~~”

She kicked her legs in protest. The combination of affection and her twitching, convulsing pussy pushed my urge to cum to the limit.

“Then here’s the final question. You want to cum together at the end, right?”

“Yes… I want to cum together…”

“Alright, let’s synchronize. On which thrust do you want to cum?”

“Umm… the 5th… maybe?”

Griiiiiiiind!!!!!!

“Nnnnn!!!!!? L-lie! I lied! Te-ten times!!”

“One more time!”

Griiiind!

“Nnghiii! Te— my nipple will come off!! No!! Fifteeeeen!!!!!”

“Understood. Then we’ll cum together on the 15th thrust… But if you cum before me… I don’t care what happens to your nipples, got it?”

As I whispered this right next to her ear, goosebumps spread across her entire body. Even her untouched left nipple was fully erect.

I grabbed her slender waist firmly, my thumbs digging into her abs.

The sound of her gulping was the signal. I pulled my hips back until only the head was barely inside—

“Then let’s begin the serious pistoning.”

“Eh? No no no! Serious is no—!”

——Pachun! I slammed all the way to her cervix.

“Daaaaahhh!!!! Nnnnnnaaaaaaaaahhh!!!!!!”

Smack!! “Aahhh!! It huuurts!!”

Smack!!! “Nngooooohhh!”

Smack!!!! “Oooaaahhh!! It’s breaking meee!”

Smack!!!!! “No more! Ohooo!! I can’t! I really can’t~”

Smack!!!!!! “Fushuuuu—!! Fushuuuu—!!! Hiiyu… hyu… hyuhyu!”

Smack!!!!!!! “Aah!? …I’m… I’m cumming! I’m cumming I’m cumming I’m cummiiing!!”

Smack!!!!!!!! “Guuuuuh—! Cum— I cameee!! Moreee! I’m sorryyy!!”

Shiori came violently in less than ten thrusts. As always, she has a pathetic pussy, but the insane contractions were desperately milking me, screaming “Cum! Cum! Shoot it!” She also locked her legs around me again to stop me from moving. She had reached her limit and her instincts were taking over. My cock was saying it was ready anytime, but punishment was necessary.

“You lying little weak pussy!!”

I pinched both of her abnormally erect nipples (which looked almost 1cm long) between my fingers and pulled them hard. At the same time, I ground roughly against her cervix.

“Nngooooohhh—!?”

The legs that were holding me released. Her feet shot straight out and tensed, her powerful thigh muscles bulging and trembling violently. Her arms did the same — fists clenched so tightly that veins stood out on her tanned skin, arms stretched and shaking. Her wet eyes were wide open, staring into space, ignoring the beads of sweat rolling down her forehead. Wet strands of hair stuck to her cheeks.

The loud moaning from earlier had stopped. In the silence, only the sound of her teeth chattering and — michi michi michi — the sound of her pussy clamping down like a vice could be heard.

“Whoa! Shit, I’m cumming!!!!!!”

Spurt! Spuuurt! Spuuuuuuurt! Pleasure shot through me all the way to the top of my head. My hips shook violently. Even after the main spurts weakened, semen kept pulsing up my urethra. But her grip was so tight I was worried it wouldn’t come out. It was almost painful.

Then suddenly, her pumped-up thighs stopped trembling. They slowly lost strength and fell wide open onto the bed. The painfully tight pressure around my cock gradually loosened.

Drip… drip… drip…

Once her vaginal pressure returned to normal, warm liquid washed over the base of my shaft. While enjoying that pleasant sensation, I released all the semen that had been held back. A full-body shiver of pleasure ran through me.

When I tried to pull out after I finished urinating (in a sense), the condom stayed inside her and only my slippery cock was rescued. Thank god — I was worried it would get trapped inside forever. Without worrying about the lake we had created between us, I collapsed beside her.

Her eyes were slightly open but probably seeing nothing.

“…Your lower eyelashes are really long.”

I kissed her dry, thin lips to moisten them. After a while of light chu chu kisses, her sleepy eyes finally turned toward me.

“…Eh? Wait, seriously? I fell asleep!? Also it’s cold!!”

“Good morning. Probably about 5 minutes. You caused a natural disaster that changed the terrain, Shiori.”

“I told you not to mess with my nipples!!”

“But you love it, don’t you?”

Slap!

“I’m gonna feel it during practice too… even with nipple covers they might show through…”

As expected of a serious track athlete, she recovered quickly even after cumming that hard.

“So what are we doing about this huge disaster?”

“We have no choice but to throw out the whole mattress… or so you’d think? Ta-daa! Rubber sheet~”

She peeled off the thin sheet and proudly showed me the light blue waterproof rubber sheet underneath.

“Whoa, that’s awesome. I want one too.”

“Your reaction is weak!”

“No, I did think it wasn’t absorbing anything at all. I just feel a slight sense of defeat knowing you predicted all of this would happen.”

Probably… she did it on purpose. Shiori’s fetish is most likely omorashi (wetting). Her preparation is too perfect, and the volume is insane. Normal people don’t empty their entire bladder like that…

“Hmph. I saw through all of the evil cock’s plans! Everything is within the palm of my hand…”

“Oh? So you were the true villain. Help me! Nipple-twisting girl!”

“Just kidding! I’m sorry! I’m just a weak, pathetic pussy! Please help me clean up!!”

We playfully wiped each other’s bodies with the towel that had been by the pillow.

I was left in just my underwear. She put her bra back on and wrapped a towel around her waist.

“Okay! Hold the other end— We’re going to the bathroom like this without spilling!”

We each held one end of the rubber sheet and carefully carried it to the bathroom.

“Why do we have to do a half-naked relay race after sex?”

“It’s all the nipple-twisting man’s fault~ Ah, wait a sec. The place where the pee got is starting to itch. Can I scratch?”

“…If you don’t mind spilling it, go ahead.”

While saying stupid things, we reached the bathroom, threw the sheet in, and took a shower together.

“Hey! There’s still a condom inside me!”