MBM-238 Discovered that my sister liked to masturbate and the ending

The content of the over 1 hour video above is about the love story of a young man who secretly fucked his younger brother's wife. He accidentally passed by and saw his sister-in-law masturbating in the bedroom. The young man became sexually aroused. Suddenly realizing that his younger brother had gone out since morning, he immediately went in to "help" the girl who was... pleasuring herself. At first the wife seemed shy, but after seeing her husband's huge penis, her expression changed, the word "porn" began to appear on her face, and the two began to "have sex" together, of course. They are always wary of outside noises, who knows what might happen if their husband/younger brother comes home.