I was astonished to learn the following about Victor Hugo (1802–1885), author of Les misérables (1862) and many other texts.
[Hugo’s] love affair with Juliette, though discreet, was another of the worst kept secrets in Paris. By the time the item went public, Victor and Adèle had agreed upon a discreet open marriage, exactly as his own parents had, a thoroughly contemporary arrangement. She slipped off through the escalier dérobé to see Sainte-Beuve and Victor left the front door to meet Juliette — and others.