Big Mouth's Big Mistake

Just felt like writing about this incident which happened somewhen last week. The Big Mouth in my class who can't seem to stop talking, nor turn down the volume of his unwelcome speeches, said something which would make all dead English teachers roll in their graves.

So there I was, showing the class how something is to be done, and upon completion, asked the customary "All of you done?". Mr Big Mouth, who happened to think that he has a superb command of English with a flourish, replied immediately (which is a habit that irritates me like mad!) in a loud and obnoxious tone "Yup! Been there, done that!"

It was so revolting I nearly fell off my chair! Does he even know what that expression means? Is it just me, or are people who think they are so smart (but are not, actually) simply unbearable? I marvel at myself for having put up with his nonsensical comments for as long as I have. Come end of semester, quickly, please!!!