“There are 30 seconds of perfectly groomed young women in the back-arching, pupils-dilating throes of carnal abandon – either in flagrante delicto with a partner, or in the bath, or pressed against a window, that sort of thing” in the current UK television ad for a Durex feminine lubricant. The accompanying music is “Der Hölle rache,” the Queen of the Night’s stratospheric vengeance aria from Mozart’s Magic Flute.