boxer blunder

What happens when a guy puts on his boxer shorts backwards. The error is compounded when he fails to notice the error until he unzips his pants to piss after waiting until the very last minute to go, usually resulting in an embarrassing "accident ".

Todd: Why are you holding your backpack over your crotch?
Bill: I pissed my pants, man!
Todd: WTF!
Bill: Boxer Blunder dude.