Reading the introduction to The Portable Jung, I found something which was all too predictable. Jung was relating a story of meeting Freud in Vienna. Accompanying Jung was his wife, who was particularly aware of her husband's work. Freud's wife turned out to be utterly in the dark as to the nature of his industry. Not so with her attractive young sister. Jung remarked, "Soon I met Freud's wife's younger sister. She was very good-looking, and she not only knew enough about psychoanalysis but also about everything Freud was doing."
Does the rest of the tale need telling? Sometimes a sister-in-law isn't just a sister-in-law.