Where does the term "excuse my french" come from?

Answer 1

What is the origin of the phrase pardon my French?

This phrase, in which French refers to "bad language", is employed
when the speaker feels compelled to use an obscenity despite having
listeners who might be offended. It's a late 19th century euphemism
which first appeared in Harper's Magazine in 1895.

It is thought that the term French is employed in this sense as it
already had a history of association with things considered vulgar.
As far back as the early 16th century, French pox and the French
disease were synonyms for genital herpes, and French-sick was another
term for syphillis. The OED [Oxford English Dictionary] also equates
the adjective French with "spiciness", as in French letter for
"condom", French kiss (1923) and French (i. e. "sexually explicit")
novels (from 1749).

Answer 2

Some English-speakers stereotype the French as permissive about
anything risqué. This was particularly true a hundred years ago when
the phrase took off as an "apology" for swearing. "Excuse my French"
or "Pardon my French" isn't just play-acting that you're speaking a
foreign language. It's also a bit like saying, "I know those words are
naughty - but maybe I could get away with behaving like that in
France, where people are more tolerant of obscenity."

Answer 3

In this country, very few people speak other languages. Therefore, when they try to speak French, they do it so bad, that they must apologize

Answer 4

I think people use that expression in a derogative way toward the French and their langage .