The line comes from the Spy, the French-accented infiltrator class in Valve's Team Fortress 2, a team shooter first released in 2007 where each class has hundreds of situational voice responses. Clipped from gameplay, the reaction escaped the game onto soundboards and into edit culture alongside other terse game callouts like Enemy Spotted, because it sums up disbelief in two seconds without needing context. It remains popular for mod showcases, machinima and reaction edits where a polished character is forced to confront something deeply stupid or unsettling.