Refering to any person who is in a bad mood. An updated verson of the phrase "poopy pants". Muddy t-bar refers to some one who has shat their g-string and it has started to boil over.
I am sick of these damn auto mechanics, they all have muddy t-bar's.

Don't worry about him, he's just sporting a muddy t-bar.
by Swizzle stick February 1, 2007
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