The boy continued to fuck Lisa, grinning at feeling her tight pussy around his cock.  "Hah.... you haven't had many men before, have you?  Too bad for you... you're so nice and tight," he said excitedly.  As his cock swelled, the barbs started to stiffen, scraping along Lisa's inner walls.<br/><br/>"Aah!  No, stop, it hurts!  Stop it!" Lisa screamed, getting louder as the barbs scratched her harder and harder.  Every time the boy withdrew, she felt the barbs scratch her pussy walls, causing her to cry out again.  She was sobbing after only a few moments, her sex feeling like it was on fire.  "No... no, stop, please!  I can't take any more..." she continued to beg, the fight leaving her voice.<br/><br/>Sonia watched her friend's ordeal with growing fear, shaking her head as Yuki threatened to make her go through the same.  "No, please!  Anything but that, please, I'll do anything!" she quickly begged.  Her begging was quickly replaced by moans as Yuki sucked on her breast, and she thrashed in her bindings again, this time out of desire rather than any attempt to escape.