Suzanne Westenhoefer performs at the Post Office Café and Cabaret, 303 Commercial St. in Provincetown, from Saturday, July 31 through Aug. 31, 7 p.m. Westenhoefer, the first openly lesbian comedian to perform on Late Night With David Letterman, celebrates 25 years in comedy with an unscripted show that dismantles stereotypes. Tickets are $25 at postofficecafe.net.