I got an email the other day from TheatreFace.com member Lauren asking about the gun gag for Who's Afraid of Virginia Woolf. In case you're unfamiliar, at one point George threatens Martha with a shotgun, but when he pulls the trigger, a parasol pops out. It's a fun moment -- but not a simple gag for the props department. Lauren was wondering how people built the gun. I remembered that a couple y…