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2.
Gay Until Proven Otherwise
Ayo, that nigga is GUPO as fuck.
by Successful Black Man September 22, 2013
 
1.
Gay Until Proven Otherwise
GUPO: This is code for straight girls to describe that super hot guy at the pub who has clean fingernails, is wearing a pink floral shirt BUT is drinking beer from a can. 'Do you think he'll ask me out?' 'Be careful, he's definitely GUPO'.
by BUPO January 06, 2012
 
3.
Gay Until Proven Otherwhise. Someone who hasn't been seen dating anyone of the opposite sex for quite some time/ever. Friends or colleagues will assume that such a person is gay until they have seen "proof" to the contrary. Mostly used about women.

Derived from the thumb rule of justice: "Guilty until proven otherwhise."
Oh, you know, nothing much - so the usual. She's a GUPO if I've ever seen one.
by WillVisitIndia July 06, 2010