When I came home from my boarding school for the summer vacation, I saw a strange girl's panties right in front of me. They were sisters brought over by my father's new wife. When I went to my room, my stepsister was sleeping in my bed in her underwear. My little devil sister took off her clothes and changed right in front of me, while I was feeling nervous. She brought a camera, showed me a video of my father and another sister having sex, and whispered to me like a devil, "Let's have sex in front of the camera too." She grabbed my overly erect dick and pressed her miniskirt ass against my face, so I couldn't bear it anymore and attacked my stepsister and made her scream with her hard pistoning!