Wiktionary
ass backwards
a. (alternative spelling of ass-backwards English)
Wikipedia
Ass Backwards
Ass Backwards is an American female buddy road trip comedy film written by and starring June Diane Raphael and Casey Wilson. The film is directed by Chris Nelson and produced by Heather Rae.
The film premiered at the Sundance Film Festival on January 21, 2013. The film was made available on iTunes and VOD on September 30, 2013, leading up to the film's theatrical release on November 8, 2013.
Usage examples of "ass backwards".
So here was Malenfant, for better or worse in space once again, flying ass backwards towards the Moon -- a Moon, anyhow.