There's a video online of a little kid who looks like he's four or five.  And for some reason, the guy filming asks him to list all the SWEAR WORDS he knows.

 

So he does, and almost all of them are PG-13 words that start with "butt" . . . like "butt-head" or "butt-face."  But then he comes up with one more word you're not expecting . . . the S-WORD.