In VN’s novel Ada (1969) Marina (Van’s, Ada’s and Lucette’s mother) tells Van (the narrator and main character) that Belle (as Lucette calls her governess, Mlle Larivière) has cited to her the cousinage-dangereux-voisinage adage:
Naked-faced, dull-haired, wrapped up in her oldest kimono (her Pedro had suddenly left for Rio), Marina reclined on her mahogany bed under a golden-yellow quilt, drinking tea with mare’s milk, one of her fads.