For better or worse, my sister is very lenient with her little brother, and worries about my inability to study, so she tutors me diligently. "If you get a perfect score, I'll do anything for you," she says, so I study hard and become her own personal reverse bunny slave! At first, she reluctantly listens to me, but when I order her to straddle my dick and have sex, she starts bouncing up and down and cumming like crazy! She becomes more and more obedient, and serves me with a titjob using her exposed J-cup tits! For the three days while our parents are away, I'm going to have sex with my lewd bunny sister!