remember your audience

During a lesson on idioms:

Student: Ms. L, is 'better small than not at all' an idiom?

Ms. L: I've never heard that, but it sounds like one. Sound to me like it means you should be thankful for something even if it's smaller than you hoped. Better to have something small than to not have anything.

(Table full of boys start giggling. The reality of what I just said hits me.)

Ms L.: Ok. Who's heard the idiom, 'I just put my foot in my mouth'?

: ) WG