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1.
When a guy looks at someone else who is SOOOooo ugly or something that is epicly disturbing that their penis goes inside their body and comes out their butthole.
Dude, I had to go to the hospital yesterday because I saw this girl that gave me a Backwards Boner. The doctors were so disturbed it gave them Backwards Boners.
by IAmSoAwesomeSauce February 26, 2011