While I am completely ignorant of French upper class manners, I remember a soldier
I met in Manila, who had been in Paris prior to VE day, and then got sent to Pacific.
He spoke French well enough to be invited into middleclass French homes, and he
was impressed by the somewhat elaborate courtesies expected on departure from
them. He was expected to shake hands and say a few words to every one of the
host's family and guests. He was very emphatic that middle class French ;manners
were superior to those in America.