I was a college professor for 23 years. One day I discovered that several of my asian students had copied their homework from each other. I repimanded them to not copy each other's work, but they little bit of English did not seem to make them understand. So I said, "you may not "Monkey See-Monkey do".
I dismissed them and felt they understand that they could not copy.
Well this was not the end of it. The next week I am called into the Department Chair's office. The Asian students had an interpreter so that this conversation would not be misinterpreted. With the Department Chair heading the disucssion, she had me repeat this incident. After that the students said I called them a "monkey". This apparently is a very nasty thing to call a person in the Asian community. Apparently it is like calling them the worst thing in the world.
I was threated that I was going to be sued for saying what I did say Fortunately, the Depart,emt Chair explained everything to them (with the interpreter) how my statement is about copying -- not a bad name in the English language.
Fortunately, everything came out well. But, I really learned my lesson about ever using phrases that I grew up with in a classroom setting.