mada fada fing ding
A full-blown insult used when someone makes a mistake so bad it deserves a standing ovation for being that dumb
Mada fada fing ding! You tried to do a cartwheel and face-planted!
Mada fada fing ding! You told the teacher you're a vampire!
Mada fada fing ding! You drew a mustache on the principal's face!