When my granddaughter was about 4 she turned to my daughters boyfriend and told him to stop being facetious.. The boy friend turned to my daughter and asked what does that mean. DD said ask her. Darling GD turned and looked at him with a totally disgusted look, rolled her eyes and said. It means don't be a smart &@#
Needless say we all fell out of our chairs laughing . When we stopped we let her know it wasn't a nice word to say. But we learned to be very careful when she was around.