Expression meaning that some objective, typically one of personal resolve, has already been failed, and thus that continuing to attempt self-restraint is pointless. Comes from the Butterfly Project, where you draw butterflies on your arm when you want to cut, and if you cut before the butterfly fades, it dies.
"Yeah, I'm trying to quit drinking, but I mixed vodka in with my tea this morning, so the butterfly is dead."
by Eeveemander September 12, 2012