Recently, the older sister is interested in her younger brother's body, which has grown into a manly one. When she sneaks into the bedroom where he is sleeping, she sees his bulging crotch, a sign of his youth, and begins to play with his penis, smiling, "You're probably having naughty dreams anyway." The excitement of giving her brother a blowjob for the first time erases the guilt of incest, and she devours it like an animal.