it was so clear , so powerful , and so certain to keep him focused on sex and only sex , that even as the thought came that it was n't fair for him to use her like this , that she had n't ever asked him to come into her home and use her as his sexual plaything , he was yanking her panties down to her knees , and shoving her thighs open as wide as they would go with her legs still bound by the thin yellow fabric .