When a tiny bit of poop comes out by accident and then smears on the inside of the butt cheeks. If you pull the butt cheeks apart the poop smear resembles butterfly wings
by Elanor March 14, 2008
The Act of ejaculating onto a woman's mustache (or ''Caterpillar'') thus allowing her to wipe away the applied semen, similar to a metamorphosis of a caterpillar to a butterfly.
Dan: I blew it all all over Susan's hairy upper lip.
Tony: Can you not say that about my mom!?
Dan: Fine but theres nothing wrong with giving a girl a Dirty Butterfly.
Tony: Can you not say that about my mom!?
Dan: Fine but theres nothing wrong with giving a girl a Dirty Butterfly.
by Avpmaster132004 December 4, 2010