There was one time when me and my friends were playing cards at school and when the teacher came to class she told us to stop and get ready for class,then I suddenly yelled: "Shut the fuck up".
The teacher was shocked and didn't knew who said that and I was like with an innocent voice: "What?Who said that? O.O"
Me and my friend were laughing so hard after that and tried to do that to every teacher ever since /heh