This was published in the late '80s by Debrett's (yes, that Debrett's), and constitutes a sort of tongue-in-cheek nature guide to that most peculiar inhabitant of high society, the gentleman's mistress. In many ways, it's funny and charming and contains some cracking anecdotes, including one meant to illustrate the difference between Frenchmen and Englishmen, in which one Frenchman casually informs another that he is sleeping with the latter's wife, only to be met with "Oh yes? Tell me, is she any good at it these days?" In many other ways, it's a startling reminder that the late 1980s were as rampant with gross sexism as the late 1880s: women are referred to as mares, for instance, with all of the sexual value judgments that the word implies, and this is clearly not a world in which any sensible woman would prefer having a career to being "kept". A weird, often enjoyable, often really distressing little volume. I'm glad I have it, if only for self-educational purposes.