Commiserating with friends, acquaintances and even strangers over drinks is a favorite pastime of the middle-aged urbanite. Undoubtedly you’ve heard a few hilariously heartbreaking tales about cheating exes, thieving housemates and conniving coworkers — the San Francisco trifecta. 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: Liars, Cheats and Thieves — a topic everyone can go on and on and on about, perhaps even you.