"...Louis XV. was very polite, particularly with ladies, even with his mistresses, when in public. Whoever failed in respect towards them in the slightest manner was sure of disgrace, and no king ever possessed to a greater extent the grand royal virtue which is called dissimulation. He kept a secret faithfully, and he was delighted when he knew that no one but himself possessed it. The Chevalier d'Eon is a proof of this, for the king alone knew and had always known that the chevalier was a woman, and all the long discussions which the false chevalier had with the office for foreign affairs was a comedy which the king allowed to go on, only because it amused him."
Thing is, D'eon was a man. So our great Casanova was very wrong lol