Final answer:
The phrase 'faux pas' in the dialogue refers to a social mistake or improper behavior that Jeremiah exhibited by licking his plate and having crumbs on his shirt during dinner.
Step-by-step explanation:
In the dialogue presented, the phrase "faux pas" refers to a social blunder, mistake, or improper action that is considered unacceptable or embarrassing in a social setting.
When Jeremiah licked his plate clean and had crumbs all over his shirt, the speaker referred to this action as a faux pas because it was a breach of etiquette, especially in a formal dining situation. This improper behavior at the dinner table led to the guest being judged and potentially not being invited back.