The morning sun streamed through the window, casting a warm glow over the shared bedroom of Jack and Jill. Jack stirred beneath his covers, groaning as he stretched his sore muscles.
"Ugh, I'm so stiff," he complained, sitting up in bed.
Jill, who was already awake and stretching, turned to him with a playful smile. "You're just out of shape, Jack. You need to loosen up."
Jack rolled his eyes, but couldn't help but smile back. "Yeah, yeah. Why don't you give me a massage then?"
Jill raised an eyebrow. "Only if you take off your pants."
Jack's eyes widened in surprise, but he couldn't help but feel a thrill of excitement run through him. "Uh, okay. Sure."
He stripped off his pants, revealing his boxers underneath. Jill climbed onto the bed next to him, sitting cross-legged as she began to massage his legs.
"You're really tight, Jack," she said, her hands kneading his muscles.
"Yeah, I went for a run this morning," he replied, trying to keep his breathing steady as her hands moved closer and closer to his ass.
"You should stretch more," Jill said, her voice taking on a teasing tone. "You're so tense here."
Her hands began to knead his glutes, making lewd comments about how tight they were. Jack felt his face flush with embarrassment, but he couldn't deny the pleasure that was building in his body.
"Jill, can you...uh...focus on my ass?" he asked, his voice hesitant.
Jill smirked, her hands moving to his cheeks. "Sure thing, brother dearest."
She began to knead his ass, making lewd comments about how tight it was. Jack felt himself getting harder by the second, his body responding to his sister's touch.
"Jill, can you...uh...put something in there?" he asked, his voice hesitant.
Jill raised an eyebrow. "How big do you want it?"
Jack hesitated, but then blurted out, "Eight inches long and two inches in girth."
Jill's eyes widened in surprise, but she didn't say no. Instead, she told him to get into a doggy style position. Jack felt vulnerable, but he complied, getting onto his hands and knees.
Jill, with the dildo in hand, started to penetrate him. She told him to relax and breathe. Jack did his best, but it was difficult with the pleasure that was building in his body.
Jill started to fuck him harder, hitting his hanging balls with the base of the dildo. Jack moaned in pleasure, begging for more.
"Jill, can I have another one?" he asked, his voice eager.
Jill smirked, her hand moving to his cock. "You're going to have to earn it, Jack."
She started to fuck him faster and harder, her other hand moving to his nipples. Jack felt the pleasure build, his body tensing as he approached orgasm.
With a cry, he came, his body shaking with the force of his release. Jill didn't stop, continuing to fuck him through his orgasm.
When it was over, Jack collapsed onto the bed, spent and satisfied. Jill, with a triumphant look, told him that was just the beginning.
Jack, with a weak smile, asked her what was next. Jill, with a wink, told him to wait and see.
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