This only applies when a groupie receives a facial from three, 6 stringed musician. Preferably of the metal genre, and not necessarily all at the same time. As groupies tend to go through members, keep track of who's face you blew your load on, and compare with the other band mates. If a groupie appears on 3 of the lists, she's been marked by three six stringed instruments..... 6-6-6 ...... thus, the mark of the beast.
"...on the last tour, we hit 4 chicks with the Mark of the Beast..."