My granny used to come by the house quite often and would sit on the edge of the faucet, waiting for her visitors, such as the "good" parents of a "good" child, to come into the bathroom and "stick their heads in there." While she certainly wasn't rude, she knew there was a certain line that could not be crossed when it came to using the toilet. Sometimes there was a kid or two in the family who had gotten their grubby little paws on something a little too much and needed to be taught a lesson or two. In many cases, the granny would calmly go over the rules with them, explain why they were doing it, and then remind the parents that the time had come to make things right.