Just a little incident, more than a true "gig from hell"...

We're at the gig, I'm playing away, and I see this guy gesticulate from the side of the stage. I'm wearing headphones to hear the sequenced track, so I mouth "I can't hear you" back at this guy, hoping he would notice the cans. Then he steps up on to the stage, gently and quietly, so I'm thinking "Nah, he doesn't look like a psycho, maybe he's just lost his wallet or something". So, he approaches me. I'm still in mid song here, drumming away, headphones on, I can't hear a word he's saying. Then he reaches over, gently lifts one side of my cans off my ear so I can hear him, and says "You wouldn't have a pen on you, would you?"