Dirty Butterfly 

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

He was so scared he gave himself a dirty butterfly

Dirty Butterfly by Elanor March 14, 2008

Dirty Butterfly 

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.

Dirty Butterfly by Avpmaster132004 December 4, 2010

DIRTY BUTTERFACE

The act of fucking a butterface doggiestyle and when she turns arounds to make eye contact with you with her ugly ass face, you spray her with pepperspray or mace so you can enjoy yourself as much as possible.

Her face was so ugly, I could only Dirty Butterface her.

DIRTY BUTTERFACE by SP WD August 4, 2008