Both good and bad, my sister who takes good care of me is concerned that I can't study and diligently acts as a tutor for me. She says, "I'll do anything for you if you get a perfect score," so I've been studying hard... and she even became my personal reverse bunny girl! At first, she complained a lot, but once she straddled my penis and was ordered to have sex, she started bouncing her hips and climaxing non-stop! She's becoming more and more obedient, and with her obvious huge breasts, she's serving me with titjobs! For these three days while our parents are away, I've been enjoying sex non-stop with my sister, whose position and exposure have completely reversed!