Peek at stepsister who rarely goes out turns out to have a hobby of masturbation

Having a beautiful stepsister but rarely leaving the room made me suspicious. That morning when the house was quiet, I tried to peek at what my stepbrother was doing while in the room because he rarely left the room. I tried to open the peek and record the video carefully because I was afraid that he would realize that I was stalking him again. And it turned out that my stepsister was sighing passionately while playing with her. I tried to get into his room while shaking my hardened from earlier. Without thinking long I immediately pushed him from behind without his consent because his position was hanging out as if he was resigned to entering his dick