An act of random annoyance. This is not to be confused with the act of trolling. Schmiggly Schmaffing is annoyance that invokes rage among their victims. After completing the act, one yells "Schmiggly Schmaffin!" to increase the annoyance of the victim
Justin opens his book to page 103.
Zack says "Hey Justin! Look over there!"
As Justin is looking, Zack throws his book on the ground and yells "Schmiggly Schmaffin!"