Flashing the devil sign
"Declaring one's index and pinky digits erect, with a closed fist, in a menacing posture. . .a.k.a., in popular culture, 'Throwing up Metal'."
Billy slammed the three tequila shots then stood up and started making out with the waitress. He then pushed her away and turned to his horrified girlfriend and began flashing the devil sign. Motley Crue was blaring.