Miffy
1. Same as a wedgie 

The action of getting ones underpants uncomfortably stuck up the crack of ones ass. 

2. The act of intentionally doing the above action to another ~ 
in order to intentionally cause distress ~ 

or in a lame attempt to create humor.
1. Oh man, I got a miffy... 


2. If you say that again, I'm gunna come over there and give you a miffy.