Human Behavior Observation Experiment
Copyright© 2025 by danbaifen
Chapter 15
Incest Sex Story: Chapter 15 - That night, Allison had a nightmare. She dreamed that she had committed incest with her son and got pregnant and married, and people found out. Everyone called her a slut, a shameless bitch, and a beast... She screamed "No..." When she woke up, she was already in tears.
Caution: This Incest Sex Story contains strong sexual content, including Incest Mother Sister
Colin excitedly pushed his mother down on the bed and tore her clothes off frantically.
With a few tugs, Allison’s shirt and underwear were hanging on her body, and her snow-white breasts were shamefully exposed to the air.
“Mom, I’m going in...”
Colin couldn’t wait to take out his thick, hard and hot penis and put the head of it between his mother’s legs.
Even through the thin layer of underwear, Allison could feel her son’s terrible burning sensation.
“Wait ... wait a minute!”
Allison blushed and reached to the bedside, tremblingly took out the surprisingly large condom from the drawer and handed it to her impatient son.
“Put ... put this on, and mom will ... let you in...”
She turned her head away with a red face, not daring to look directly into her son’s burning eyes.
Colin took the condom and put it on his thick penis in two or three strokes.
The purple-red glans is raised high, with hideous meridians on its surface.
Allison couldn’t help swallowing as she looked at her son’s majestic penis. She felt an indescribable commotion in her lower abdomen.
“I love you mom...”
Colin leaned over and kissed his mother’s red lips gently, pressing his hot cock against her muddy hole.
Allison closed her eyes in shame, feeling the hard object pushing into her body inch by inch.
“ah...”
Allison couldn’t help but moan when the glans squeezed open the tight vagina.
“The penis is too big ... The size of the son’s penis is not at the same level as his father’s.”
Even with a condom on, Allison almost fainted from the extreme soreness and swelling she felt.
Colin held the cock and slowly pushed it deep inside.
Allison could clearly feel every vein on the blade of flesh, scraping against the fragile inner wall.
With the obscene sound of “gurgling”, Colin finally immersed the entire penis into his mother’s vagina, reaching the heart of the flower.
“Mom, I’m finally home...”
Colin panted into Allison’s ear, his tone full of ecstasy and satisfaction.
“Yes, at first he had been living in my womb, and then I brought him into the world after the painful birth. Now he has finally returned to his hometown and occupied the softest and most secret place of my mother.”
Colin began to thrust slowly, his thick and long cock rubbing against the sensitive cervix repeatedly.
The pleasure flowed through her body like an electric current. Allison couldn’t control her twitching and spasming, her legs tightly wrapped around her son’s strong waist.
“It feels so good ... So this is what it feels like to be penetrated by my son...”
“Mom, you’re so wet and hot inside...”
Colin increased the speed of his thrusts, hitting the deepest point with each thrust.
“Don’t worry, this is my home from now on ... I will come home every day and feed you well...”
Allison whimpered and nodded, raising her hips to meet her son’s thrusts.
“My son has taken possession of me and is riding on me. I can never turn back. But I am willing to become his woman and let him settle down in my body forever, forever...”
The “pa pa pa” sound of flesh hitting each other and the “gurgling” sound of water intertwined, playing an obscene melody in the bedroom.
Allison hugged her son tightly, whispering in his ear: “Mmm ... son ... so good ... Mom loves you...”
Colin shuddered when he heard that, and thrust his hips up quickly for a hundred times, then with a muffled groan, he poured all the hot semen into the condom.
The scalding heat flowed through a thin membrane, stimulating Allison to climax as well.
“Ahhh...”
Allison screamed, her pussy contracted violently, releasing a large stream of vaginal fluid onto her son’s glans.
Colin trembled with pleasure and thrusted dozens more times, wishing he could stuff his testicles into his mother’s body.
Finally, everything returned to calm.
Colin pulled out of his mother’s body, panting, took off the condom, tied a knot and threw it aside.
The thick semen sloshed in the transparent rubber bag, stimulating Allison’s vision.
Colin hugged his mother lovingly and gently stroked her sweaty back.
“Mom, it’s great, isn’t it? Let’s live like this from now on and never separate again, okay?”
Allison blushed and nodded, burying her face in his chest.
Yes, from now on, she is her son’s woman alone. No matter what happens, she will keep this secret and accompany her son through life...
The night deepens, and the moonlight outside the window is like water.
After the passionate lovemaking, the mother and son hugged each other quietly and whispered in the bed.
At this moment, it seems that they are the only ones left in the world.
They all knew that this forbidden love was doomed to fail.
But at this moment, they just want to put everything aside and indulge in the bliss of being in harmony with each other...
From then on, their lives had new meaning.
Allison is no longer the starting point of her son’s life, but his eternal home.
And Colin will regard his mother as his home until the end of time...
That night, Colin was like a hungry beast, taking possession of his mother’s body again and again.
They had sex crazily, and the obscene sounds of water and flesh hitting each other echoed in the bedroom.
Colin’s thick cock went in and out of his mother’s pussy, reaching the deepest point each time.
The sore, swollen and numb pleasure came over her and Allison screamed in ecstasy, her legs tightly wrapped around her son’s waist.
“Ahh ... son ... it’s too deep ... my vagina is going to break...”
Allison trembled as she endured her son’s invasion. Her pussy kept contracting and tightly gripped the big cock that made her feel extremely happy.
Colin’s eyes were red as he thrust in and out as fast as a pile driver.
The thick and large glans broke through the cervix again and again and penetrated into the mother’s uterus.
The deadly pleasure made Allison’s scalp tingle and she almost fainted.
“Mom ... your pussy is so good at sucking ... I’m going to cum in you...”
Colin growled and hugged his mother’s waist tightly, and the hot semen spurted out and poured into her body.
Streams of thick semen washed over her uterus through the ultra-thin condom, and Allison screamed as she reached orgasm.
The vagina contracted like a spasm, tightly squeezing the son’s penis.
At that moment, she wished her son could ejaculate inside her and let his seed take root and sprout in her belly...
This crazy sex lasted all night until Colin could no longer ejaculate.
The mother and son hugged each other exhaustedly, their bodies sticky with each other’s body fluids.
“I love you mom...”
Colin kissed his mother’s forehead gently and hugged her limp body tightly.
Allison closed her eyes and buried her head in his arms, feeling sweet and ashamed.
She has completely fallen and become a slave to desire...
The next morning, Allison woke up from her son’s arms and found herself sore all over and with mud between her legs.
But looking at her son’s peaceful and contented sleeping face, she felt that it was all worth it.
“From now on, I am his woman and his mother. I will keep this secret for the rest of my life...”
She turned her head to look at the bedside table, where there were several knotted condoms. They were used by her son last night, filled with his thick essence. Thinking of that thing going in and out of her body, she bit her lip in shame.
“Oh my God, what have I done? How could I commit incest with my own son...”
“One ... two ... three ... seven ... there’s another one...”
Allison counted the condoms thrown on the ground and found that her son had filled eight condoms!
We did it ... eight times ... oh my god...
“God, please forgive my sins. I swear, I will never do this again. I will be a good mother and stick to my bottom line. I can no longer let desire dominate me and must get rid of my attachment to my son.”
Allison was lying on the bed, struggling with her conscience, unaware that Colin next to her had already woken up.
He held his mother in his arms and kissed her forehead softly.
“Good morning, mom.”
Colin had a smile on his face, looking very satisfied.
“You gave me a blast last night.”
Allison blushed at his blunt and explicit words.
“You ... you are not allowed to mention it again! Last night was a birthday present for you, just pretend it never happened, and don’t ... do that again!”
Allison glared at him in mock anger and struggled to get up.
But Colin would not let her go. He turned over and pressed his mother under him.
The desire of morning erection pressed against the center of my mother’s legs, hot and hard.
“Don’t be in such a hurry to leave, Mom ... let me have fun again, okay?”
He kissed me with a smile, and his big hands had already reached into my mother’s nightgown and were ravaging her breasts.
“No! Let me go!”
Allison struggled in fear, but her pussy became wet despite herself.
Her spirit and her body were at odds with each other, and she found that she could not resist her son’s advances.
And Colin also noticed this.
He smiled smugly, his fingers already pushing open the labia, rubbing the entrance.
“Mom, you obviously want it too ... You’re all wet down there...”
Allison was so ashamed and angry that she scratched her son’s back hard.
“It’s all your fault! You little bastard, you made Mommy like this!”
Allison cried and pounded his chest, her vision blurred by tears.
She hated herself for being so weak and unable to resist her son’s temptation.
Colin kissed away his mother’s tears tenderly and slowly pushed his lower body forward.
“Mom, don’t cry ... I will take responsibility for you.”
The iron-hard cock stretched the mother’s passage inch by inch and reached the heart of her flower.
“Wait, wear a condom!”
Colin put on the condom and pushed his cock back into his mother’s body.
“I swear, I will never leave you in this life...”
Allison tensed her body, but her pussy sucked her son’s cock with great enjoyment.
Colin opened and closed his penis without saying a word, and his thick glans rubbed repeatedly against his mother’s sensitive spots.
The pleasure came like a tide, and Allison moaned in unbearable pain.
“Ah ... son ... be gentle ... mom can’t bear it anymore...”
Allison whimpered and begged for mercy, but her body honestly responded to her son’s.
Colin became even more wild after hearing this, and hit his mother’s cervix hard with every thrust.
The hot giant galloped inside her body, and the rapidly accumulating pleasure made her dizzy.
Colin realized that his mother was on the verge of orgasm, and he swung his hips rapidly, finally bringing her to the top.
“Aa...
I screamed and convulsed, with large amounts of vaginal fluid gushing out and splashing onto my son’s glans.
Colin growled, pulled out his cock, tore off the condom, and sprayed his hot semen onto his mother’s chest.
The milky white liquid splashed on the red and swollen nipples, which was obscene and erotic.
Colin spread them with a sense of humor, smearing his mother’s breasts until they were shiny and smooth.
“I love you mom...”
He kissed his mother again and rubbed the liquid onto my face.
Allison collapsed on the bed, almost unconscious.
“The ninth time...”
“Why, I have made up my mind not to fall, but I still can’t resist the temptation? I shouldn’t be like this, but the pleasure my son brings me is really wonderful...”
Looking at Colin’s loving eyes, Allison felt a pang of pain in her heart.
“What can I do with you, my son ... We can no longer go back, and can only sink deeper and deeper into the quagmire of desire. I give myself to you wholeheartedly, and there is no turning back...”
Warm water poured down from above her head. Allison closed her eyes and tilted her head back, letting the clean water wash away the dirt on her body.
The semen that her son ejaculated into her body last night had dried up and formed a thin layer of white marks.
Her face flushed red, and she scrubbed it hard with a bath ball, trying to erase the evidence of the crime.
When I was halfway through taking a shower, the bathroom door creaked open.
Allison turned around in panic and saw her son walking in naked.
His eyes were as sharp as torches, staring straight at his mother’s wet body, and the huge thing in his lower body was already rising.
Allison glared at him in shame and anger, and quickly covered her private parts with her hands.
“How did you get in? Get out!”
Allison tried to sound serious.
But her body had already reacted, and her pussy became wet uncontrollably.
“Damn it, why do I feel lustful when I see him? I am so depraved...”