Wii butt is the phenomenon that occurs when a grossly out of shape person plays games such as wii bowling and the next day has a sore left butt cheek from the "bowling motion."
"Man, I was playing wii bowling last night and my arse is killing me today!"
"Yeah, you have a bad case of wii butt!"
"Yeah, you have a bad case of wii butt!"
by Miker94 January 3, 2010