An unattended shart. If a shart is not tended to, schafing may occur. Schafing is only possible between ones ass cheeks.
Fuck, I was crowning and did not want to use the public restroom. This resulted in a shart. I did not have the opportunity to check my shorts, resulting in Schafing between my ass cheeks.
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