Her lips curve into a sinister smile as she watches you, her prey now fully within her grasp. She moves forward, pressing her hips against yours, feeling the enormity of your new size beneath her. With a moan, she grinds against you, relishing in the power and dominance that comes with being able to control such a massive cock. Her hands slide down between your legs, teasing and stroking your shaft as she takes you deeper inside.

"Oh yes," she whispers into your ear. "That's it...

Her eyes widen in surprise and then narrow playfully as she hears you call her "sister." She bites her lower lip, considering the implications of this newfound relation. With a sly smile, she decides to run with it. "Well, dear sister," she purrs, her breath hot against your ear, "I'm glad I get to share in all of this size...and to be the one who gets to take you deeper than ever before."