Twisted Sisters-In-Law: One Treats the Other Like a Toy in a Mind-Bending Power Struggle

My step-sisters suddenly became my sisters and our relationship became extremely twisted. My step-sister treats my step-sister like a toy, and my step-sister is extremely timid and does whatever she tells her to do! It’s clear that they have a master-slave relationship! What’s more, my step-sister is extremely lewd! My step-sister is an excellent student and a serious girl! Or so she seems, but my step-sister’s training has turned her into an extremely lewd woman! I’m forced to satisfy their sexual needs, which has made their twisted relationship even worse. And I’m dealing with both a sadist and a masochist at the same time, and it seems like my mind and body are going to collapse. Of course, my dick is overworked…