Commiserating with friends over drinks is a favorite pastime of the middle-aged urbanite, and undoubtedly you’ve heard a few harrowing tales about backstabbing frenemies and conniving coworkers. Peer pressure your pals into taking those tales to the stage, as longstanding show Porchlight opens the mic to rookie storytellers at Open Door at the Hemlock every month. This week’s theme: Frenemies, Rivals and Opponents — a topic everyone can go on and on and on about, perhaps even you.