WHAT Is a Faux Pas ??

One day, Bertie Wooster decided to read a book.
On the very first page he came across an unfamiliar word. So he called
out to Jeeves.
"Jeeves, what is this 'fox pass'?"
"This what, sir?"
"'Fox pass', Jeeves."
"Oh, that would be 'faux pas', sir."
"Yes, dash it, whatever."
"Well sir, let me explain it this way. Do you remember last weekend
when Miss Plushbottom came to stay for the weekend?"
"Yes."
"And do you remember how on Sunday morning you pricked your finger on a rose?"
"Yes."
"And do you remember how, later, at breakfast, Miss Plushbottom asked:

 'Is your prick still throbbing, Bertie?', and you dropped a pot of marmalade?"
"Yes, Jeeves"

"Well, that, sir, was a faux pas"