In the throes of their outdoor tryst, the siblings' bodies entwined, the air thick with moans and the scent of sex, they barely notice the distant hum. As he pounds into her, she squirts, her juices drenching the grass beneath them. Their eyes meet, and they share a moment of panic. Did the man pushing the lawnmower catch them in the act? They scramble to collect themselves, hearts pounding, as they wonder if their secret has been exposed.