My mother passed away a long time ago and my father decided to remarry someone else, so now I have a step-sister. This step-sister is extremely lazy, refuses to work, and spends her days reading stories. But despite that, she is incredibly beautiful, especially with her huge breasts and soft, round buttocks. What's more, she never wears underwear! Her tiny, thin panties are no different from lingerie, and her button-up shirt can't hide her nipples! Unable to bear it any longer, I rushed to fuck her and ejaculated all my sperm inside her! But it seems like she's not angry with me, right? Knowing that, I continuously fuck her whenever I have the chance! And one time, when I went to the restroom, I accidentally caught her there, so with my mother nearby, I only dared to rub my dick against her buttocks and ejaculate. When I returned to the room, she also came to find me. It turns out she wants me to fuck her too, earlier I was the only one who reached climax, so she came to let me help her reach climax with me! We gradually sink deeper into this twisted relationship...