Scooby-Doo

So the other day my son came over to me (whining) saying his sisters were making fun of him. I said "what did they do?"
He said "They keep saying (this is the tune to the scooby doo song)
Scooby Dooby Doo
Took a poo
Dawson thought it was candy
He took a bite
his face turned white
and that's the end of the story!"
Ok, I have to admit, I started laughing, I know I shouldn't have because it did really upset my son, but the way he said it and the words just made me laugh, but I quickly gained control of myself and took care of the matter. Where do they learn these things and who sits around thinking of these words??? Oh, Shaggy's name is supposed to be where Dawson's name is.
Come to find out, my little sister Justine was the one that taught it to them. So I had a nice talk with her to tell her she can't teach my kids things like that. It makes me laugh every time I think of it, but it certainly is a song I'm sure we could have lived without learning. But I do love to laugh, so just between you and me, I kind of think it's funny!