DVRT-058 - Normally, my step-sister who doesn't see me as a man exposes her buttocks! Unable to bear it, I immediately inserted my penis and had a violent sexual encounter!

A step-sister suddenly appeared due to my parents' remarriage. Having grown up in an all-male household, I am flustered every day wondering how to interact with her. My step-sister, unaware of my feelings, seems to naturally not see me as a man, and exposes embarrassing parts of herself with an incredible lack of caution, which I find unbearable. One day, she wore tight clothing in front of me and flaunted the very vivid, plump lines of her buttocks...