OSM

Meaning "Oh shit! Moment"

Can also be spelled OS!M

From the Sookie Stackhouse books

Guy 1: Isn't that Amy chick smoking hot
Guy 2: Yeah but I hear she has a huge bush...I'd still fuck her.
*Amy is watching the whole exchange behind guy 2's back*
Guy 1: Ouch...what an OSM

by Wait................Shit September 02, 2009