Pardon my French
In the 19th century, when English people used French expressions in conversation they often apologised for it – perhaps because many of their listeners wouldn’t be familiar with French words. eg. “Bless me, how fat you are grown! – absolutely as round as a ball: – you will soon be as embonpoint, excuse my French, as your poor dear father, the major”. (The Lady’s Magazine, 1830). ‘Embonpoint’ is French for ‘chubby, plump’ (less impolite words for “fat”).
It might seem strange that the speaker, having been rather rude about the person’s appearance, felt it was necessary to apologise for the French, but not for the rudeness itself. Another possible explanation for the expression is the centuries-old bad relationship between the English and the French.
The word “French” was often used when the speaker wanted to imply sexual explicitness or rudeness: -Syphilis was called “French pox” in English and “la maladie anglaise” (the English sickness) in French. -A condom was a “French letter” in English and a “capote anglaise” (an English cap) in French. -Leaving without permission was called “French leave” in English and “filer à l’anglaise” (to leave in an English way) in French.
What the English might call the French disease, the Dutch might call the Spanish disease, the French might call the English disease and so on. Eventually, the phrase came to be used after anything that we felt was rude or impolite. The examples below use less impolite words like “hell”, “bloody” and “damn”, but the phrase is more often used with much ruder words, (which, of course, we shall not write here).
A: Hey, do you want a beer?
B: Shut the hell up, I’m trying to sleep.
A: That was rude!
B: Excuse my French, I’m just in a bad mood. When I heard that your boyfriend went on a date with your sister, I thought, that he is a bloody idiot, pardon my French.
A: Hey, can you turn your music down, I’m trying to sleep!
B: Damn you, man, I’m trying to have a party!
A: Please don’t use bad language!
B: Excuse my French, I’m drunk.