The unprotected sister and the brother who masturbates. The brother becomes increasingly excited as he watches his sister start masturbating without noticing, reaching out to touch her. However, the sister, though hesitant, refuses to be touched. Yet, succumbing to her brother's demands, they begin mutual masturbation where they only watch and do not touch. Despite saying they would only watch, both become excited and close in, with their genitals just 3 centimeters apart...
