I patiently persisted for another half minute, but my mother’s voice calling my name grew louder and louder, and her knocking on the door became more and more urgent.

I stopped thrusting, and my sister looked like she was about to be in big trouble.

“There’s no other way, it seems I have to agree.” I said helplessly, “If I don’t agree, Mom will definitely think there’s some military intelligence involved.”

“Okay~” The younger sister was flustered and at a loss.

I feigned a sleepy tone and asked, “Mom, what’s wrong? I just fell asleep?”

The knocking stopped abruptly. After a moment of silence outside, Mom said slowly, “Why haven’t you said anything for so long?”

“I was asleep and didn’t hear you. Is there something you need?”

There was another long silence outside the door. My sister and I hugged each other tightly. Looking at my sister’s pretty face, which was flushed and full of spring in my arms, I was filled with nervousness. An indescribable excitement rose in my heart, and I was so excited that I couldn’t help but tremble all over.

My mother was standing outside the door, just a door away, but inside the bedroom, I was inserting my penis between my younger sister’s legs, my penis pressed tightly against her vaginal opening, committing incest.

The thrill of adultery and immorality made me unable to resist thrusting my hips again, continuing to pump into my sister’s leg.

My younger sister stared at me in astonishment, her pretty face filled with disbelief, as if she couldn’t believe that I would dare to do something so bold in such a tense atmosphere.

“What are you doing…?”

My sister gently pushed against my chest to stop me, and said softly, “Mom is outside.”

“fine.”

I grabbed my sister, who was trying to escape, and pinned her down: “Mom can’t get in, so don’t move around so Mom can hear you.”

“No…” The younger sister struggled slightly, her face full of worry, fearing that her mother would find out.

*Smack!*

I gently patted my sister’s delicate bottom, making a soft, crisp sound that was quite jarring in the quiet night.

I lowered my voice: “If you don’t want Mom to hear, then behave yourself.”

As expected, my sister dared not make any more rash moves, but instead bit my lip hard in protest.

My mother’s cool voice came from outside the door again. Her voice was broken and she felt bad for disturbing me so late: “Mom… Mom is fine.”

I gestured for my sister to lie face down on the bed, and she resisted me slightly, though reluctantly.

While answering my mother, I pulled at my sister and said, “Oh, it’s alright as long as nothing’s wrong.”

My sister knelt on the bed, half willingly and half forced. I pinched her waist, signaling her to stick her little bottom out.

The younger sister braced herself on the bed with her arms bent. Her body was half-stiff, and her back was as hard as if it had been nailed down. She was unwilling to make such a shameful move.

I couldn’t help but feel a little anxious. I gently patted my sister’s round buttocks, and pressed my fingertips against her vulva through her wet panties, which carried a hint of threat.

Feeling threatened in her private parts, the younger sister’s pert and tender buttocks trembled involuntarily. She pouted slightly and slowly assumed a kneeling position with her buttocks sticking out. As her slender waist sank down, her beautiful buttocks rose, and her alluring body outlined a captivating curve.

Looking at my sister on the bed, I breathed heavily, and my penis was painfully hard.

The younger sister’s long black hair was loose, so you couldn’t see the expression on her face.

Her fair, delicate arms were bent, her slender hands gripping the sheets on either side of her face. Her soft waist slumped slightly, and her full, pert buttocks were raised high towards me. Her nightgown, due to her posture, fell to her chest and neck, revealing her jade-like waist and perfect long legs.

The younger sister was completely naked from the chest down, except for a thin, soaking wet pair of underwear.

Looking at my sixteen-year-old sister with an excessively good figure, my eyes turned red. I immediately grabbed her slender waist, slightly thrusting my hips. With a soft moan from my sister, I deeply inserted my penis between her legs. As my waist hit her beautiful buttocks, the head of my penis emerged from in front of her legs and pressed against her lower abdomen.

Whether intentionally or unintentionally, my sister closed her legs together, and her buttocks tightened, making the cleft between my buttocks even tighter, which made me gasp with pleasure.

The sound of the door lock turning rang out, and Mom asked in a cold voice, puzzled, “Why is the door locked today? Don’t you usually leave it unlocked?”

“Oh, I must have just locked it without thinking. I didn’t even notice.”

The mother asked gently, “Would it be convenient for you to open the door for me?”

Looking at my sister, who was in a doggy-style position and pinned beneath me, my heart nearly leaped out of my throat. I gently thrust my penis in and out, slowly penetrating between my sister’s buttocks, the thick shaft rubbing against my sister’s beautiful, tender vulva time and time again.

Open the door? If I were contemplating suicide, I might open the door.

I tried to keep my tone normal: “Mom, let’s talk about it tomorrow.”

“Well, it’s nothing really,” Mom said hesitantly. “I just wanted to see Xixi, but her door was locked, so I just wanted to pass through your room.”

I pinched my sister’s firm buttocks, and she let out a soft moan. I could clearly feel that her legs were getting even wetter. “Why don’t you just knock on her door?”

“I was just afraid of disturbing her rest.”

Hearing this, I knew perfectly well that my mother’s real intention was not this; this excuse was 99% a way to check up on my sister and me.

I gave my sister’s plump buttocks a hard bump to express my displeasure: “Aren’t you afraid of disturbing my rest?”

The girl’s body suddenly tightened, her legs and buttocks clamping even tighter, clearly feeling very uncomfortable under my deliberate teasing.

“Alright, alright, you should get some rest too.”

The mother didn’t bother her too much, and since she couldn’t directly express her intentions, she left on her own after failing to find out anything.

I didn’t know if my mother was really leaving or not, but she continued to slowly thrust in and out of my sister’s vagina, enjoying the long, lingering pleasure of the friction between the siblings’ genitals.

With each thrust, my sister let out a soft moan, like a cat’s meow, like a fairy’s song. Hearing this, my penis grew harder and harder, and I thrust faster and faster until finally, like a torrential downpour, I poured out my juices, thrusting wildly without stopping. I didn’t even care that my mother might be eavesdropping outside the door. My hard thrusts made my sister’s beautiful buttocks slap loudly, and she kept panting and moaning.

To avoid disturbing her mother with her moans, the younger sister even had to bite her nightgown to prevent herself from letting out a high-pitched scream.

The moon hung in the western sky, and the stars shifted. I don’t know how much time had passed, but I know that my sister, who had climaxed countless times, had become limp and weak from the relentless butt-fucking. She could no longer stick out her little butt, and could only maintain the rear-entry position by me supporting her waist.

“XiXi~ Sister, I’m going to cum!”

I gritted my teeth, and my penis continued to thrust rapidly in and out of my sister’s muddy vagina.

“Mmm~”

The younger sister did not respond. Half of her pretty face was pressed against the bed, her red lips were slightly parted, drool was dripping from the corner of her mouth, her eyes were unfocused, and her expression was slightly dazed. She could only rely on instinct to let out soft moans from her throat.

“snort!”

I let out a muffled groan, then pressed myself against my sister and lay face down on the bed. My penis, deep inside her buttocks, throbbed, and streams of thick semen filled the space between her legs.

“Hmm~”

The scalding heat swept over her private parts, and the younger sister gripped the sheets tightly with her slender hands, her youthful and beautiful body trembling slightly.

Her anus moved, her two elastic buttocks contracted slightly, gripping my penis as if she were actively massaging it for me.

I gasped from pleasure, feeling a surge of wetness as my penis pressed against my sister’s vulva. Her sensitive, tender vagina also gushed out copious amounts of vaginal fluid, bringing this intense buttock-fucking session to a perfect close with an orgasm…

“It’s so heavy! Bro, get up!”

I don’t know how long she had rested, but my sister, who was pinned down by me, murmured something weakly.

“good.”

I was so excited I almost fell asleep right there on my sister’s body.

I fought off my sleepiness and carried my sister, who had gone limp like a puddle of water, to the bathroom.

My sister’s crotch and panties were covered in my semen, a complete mess. Her two slender, beautiful legs were also covered in traces of my semen.