As an American myself, it felt like one should know how precisely how many filet mignons one wanted when ordering in a restaurant, rather than leaving it up to interpretation.

Didn’t realize then that “couple” in British English was almost certain to mean exactly two. I wonder if Americans also used it in that sense back in the 1970s when that episode was filmed, or if that is actually a bit of a shibboleth goof — the “American” actor was of course British, like everyone on the show except John Cleese’s real-life wife Connie Booth.

(Now that I think of it, as Booth was a co-writer, she probably would have caught this mistake if it was in fact a difference in American vs. British English. I imagine instead the American meaning has drifted toward less specificity over time.)