It was a bad idea for a lesson plan.
Today’s idioms were “Don’t quit your day job,” and “When pigs fly.”
Not only did I have to teach what these expressions mean, I had to warn my students not to say these things because they are insults.
In other words, it was a wasted class session.
These expressions are very nuanced.
Nuance is an advanced concept.
Today’s students were beginners.
I sure hope they don’t come back to class tomorrow with a black eye.
Sarcasm is a bad idea for a lesson plan.