As of July 16th 2010, the word "dun goofin" is a cuss word.
It can be used as substitute for fucking.
This term came to be from some wannabe scene slut, Jessi Slaughter (kerligirl13), on crying on
Youtube, because everyone on
tumblr started to troll on her for being such a bitch. Her
father, who is to blame for his daughter, shouted "you done goofed" at us as he threated to call the cyber police on us.