Answer:
Faux pas is a French expression that literally translates as: misstep. In English it is most often used in the context of mishaps or blunders within a social context. As such, it is used to refer to the violation of certain social norms or etiquette rules.
The origin of the phrase goes back to the times of the King of France, Louis XIV, in whose reign dancing was very important and in which, a misstep could cause you from being vanished from the aristocratic salons.