Stumbling upon his step-sister in the throes of self-pleasure, the curious brother can't help but watch as she fingers her wet slit, her moans growing louder with each thrust. Her eyes widen in surprise, then excitement, when she catches him peeking. She beckons him closer, offering her mouth and hands to bring him to the edge. Together, they explore each other's bodies, their mutual pleasure building until they both cum, her swallowing his load eagerly.