Stab Someone In the Back By EvilSeptember 18, 2014February 14, 2019Popular Expression Stab Someone In the Back = betray someone * You can call the person who betrays a “backstabber.” Ex: I trusted her with my secrets, but she “stabbed me in the back” by telling everybody. Ex: We were best friends, but he “stabbed me in the back” by sleeping with my girlfriend. BACK to Popular Expressions