The worst attempt at inserting women into a group of cool that coensides with their sexuality. It was most likely made by a sorry individual who felt that calling a group of girls "guys" was a moral sin. Anyone who uses the word should be castrated and decapitated, because no girl would be stupid enough to use a word like "dudette."
Brian before saying "dudette": an average teenager trying to pick up girls
Brian after saying "dudette": head off, dick off, dead with blood spattering everywhere