The brother lay sprawled out on his bed, lost in the throes of his daily self-gratification session. His eyes were closed, and a soft groan escaped his lips as his hand moved rhythmically beneath the sheets.
Suddenly, the door to his room swung open, and his sister walked in, catching him in the act.
"Ew, gross!" she exclaimed, covering her nose with her hand. "Can't you do that somewhere else?"
The brother laughed, not bothering to hide his embarrassment. "Jealous, sis?" he taunted.
His sister rolled her eyes. "Please. I've got better things to do than watch you jerk off."
But as she spoke, she moved closer to the bed, a mischievous glint in her eye.
"Hey, watch it!" the brother protested, trying to cover himself.
But it was too late. His sister had already grabbed him by the balls and was pulling him towards the bathroom.
"Come on, let's teach you a lesson," she said, a wicked smile playing on her lips.
The brother struggled, trying to break free from her grasp. "Let go of me, you ball-buster!"
But his sister was too strong. She forced him to sit on the toilet lid, and he protested, calling her a "sadist" and "cruel."
With a wicked grin, his sister pressed his balls against the lid and sat on it, crushing them.
The brother yelped in pain, and his sister laughed, jumping her butt on the lid and crushing his balls even harder.
"Stop it, you sadist!" he cried, but his sister only laughed harder.
"Oh, come on. You're such a wimp," she taunted.
The brother, in agony, begged her to stop, but she only laughed harder.
Suddenly, his sister realized that she had crushed his balls too hard, and he screamed in pain.
She quickly got off the toilet lid, and the brother fell to the floor, holding his groin.
His sister, realizing the severity of her prank, felt a pang of guilt.
"I'm sorry," she said, trying to help him.
But he pushed her away, calling her a "monster" and "heartless."
The chapter ended with the brother lying on the floor, in pain and anger, while the sister stood over him, feeling regretful and confused.
Their relationship would never be the same again. The power dynamics had shifted, and the sister had asserted her dominance in a way that the brother would never forget.
But as she walked out of the room, she couldn't help but feel a sense of satisfaction. She had taught him a lesson, and she had enjoyed every minute of it.
The end.
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