i'm having fun mum

said when anyone says something extremly dumb, or makes a shit call. basically it shuts them down.
you say it in a retards sorta voice.
came from the add where the kid is on the monkey bars and says "im having fun mum"

"are the sun and the moon the same thing"
"i'm having fun mum"

by nikki.6 January 07, 2008