Adam fucks his sister in earnest

"Damn, you're tight." The pressure on Adam's cock after his initial thrust was immense. But he wanted to fulfill the wish of his sister and completely bury his shaft balls deep inside her, and quickly decided to make another attempt. First he withdrew his cock to be able to leverage additional ****, making his sister suddenly feel empty again and causing her to whimper in disapproval, only to follow it up with a renewed vigorous thrust, which caused cries of ecstasy to emerge from Sarah's mouth.

Sarah got overwhelmed by the increased friction and deep penetration by her brother's cock, which was bigger, longer and thicker than anything else that she had ever taken inside her. Adam's thrust brought her another jolt of pain and pleasure, so much, too much. It put her over the edge, made her feel lightheaded and her vision became blurry, while the walls of her pussy constricted and clamped down on her brothers thick fuckstick: "Aaaaaah, fuuuuck!"

Adam equally felt her tightness with his thrust, he could feel the contraction and the squeezing of her muscles, while he saw the body of his sister shake uncontrollably. He knew that he was close to release as well. But when he looked down, he had only gained perhaps half an inch, and with that he wasn't content.
He continued to withdraw and thrust again, now more quickly and with more speed. His sister moaned with every thrust.
"Fuck, you're so tight. One could think that it's you, who is the virgin here. I guess this kinda is your first time as well. Your first time with a real cock. You never had one as big as mine, did you?".

"Ahhh, no!"

"I'm gonna stretch that tight little pussy of yours really good!"

"Ahhhah."

"When im done with you, you won't even be able to feel any of those small dicked losers, like your boyfriend Mark. Would you like that?"

"Yeees!"

Over and over Adam pushed inside her, drawing out more moans and cries from his sister, delivering pleasure with every thrust.
"I am gonna make you a big cock slut. My slut! Tell me how much you want it!"

"Ahhh. I want your, hrrng, your big cock Adam. Ahhh. Fill me uuuuuuup!"

Now Adam could feel his release approaching, and he had almost done it. He withdrew once more, and put all his strength in a final thrust. And with it, he completely buried his thick eleven inch shaft in his sister's warm, wet, and so very tight pussy. The pressure and pleasure was too much, making Adam experience his strongest orgasm yet with his newly "Growth X" enhanced monster. He could fell his cock pulsing, as cum-shots erupted from his shaft, completely filling up his sister's pussy, shooting his jizz deep inside her.

That made her cry out yet again, her eyes rolled back and he could see her body spasm. His powerful orgasm wouldn't stop either, and while he could feel one spurt after another, he felt lightheaded himself. He looked down at his sister, her face had already rolled sideways, clearly ****. The orgasm seemed to take all his remaining energy as well, and with all the exertions his body had to endure that day, his Growth-X powered transformation, several major orgasms, and this prolonged fucking, finally took their toll, and it wasn't long before Adam collapsed onto Sarah. He closed his eyes and let himself rest, with his cock still buried completely deep inside his sister.