A stepsister gives her brother a condition to show her his cock after she found him masturbating

A man is in the bathroom alone as he plays with his cat. He jerks off his dick until it gets super hard. As he continues to masturbate his dick, his step-sister opens the bathroom door without knocking and finds him red-handed jerking off. The guy becomes furious and asks his sister to get the fuck out of the door since it was none of her business. The step-sister seduces her brother and tells her that she will not tell anyone if he shows her his cock. The guy tries to refuse because he thinks that it was an abomination before everything got super nasty.