you don't know where it's been

you don't know where it's been

You have no way of knowing whether the thing we're discussing is covered in germs or not. Billy, drop that gum right now! Yuck, you don't know where it's been! Don't go picking up some random piece of clothing off the side of the road—you don't know where it's been!
See also: been, know

You don't know where it's been.

Do not touch something or put it in your mouth, because you do not know where it has been and what kind of dirt it has picked up. (Most often said to children.) Mother: Don't put that money in your mouth. You don't know where it's been. Bill: Okay. Take that stick out of your mouth. You don't know where it's been.
See also: been, know
Full browser ?