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When an underwear company sells boxer shorts without a button fly and claims that the fly will not open. Those who buy these underwear products exhibit a leap of faith in regards to the concealing abilities of the fly. Thus, the boxers have a "fly of faith" which has a tendency to fail at the most inopportune moments.
Guy 1: I bought some boxers yesterday that didn't have a button and then I had a sleepover with Mary and the fly gapped and she could totally see my thing! Now she'll never have a sleepover with me ever again.
Guy 2: You shouldn't have trusted the fly of faith. I always buy my boxers with a button.
Guy 1: True that.
by hanesdude July 07, 2009
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