Neil Campbell and Paul Rust are like those college geeks who would taunt the frat boys — yucksters who’d stick a sleeping jock’s hand in a bowl of warm water. Their latest sketch show, Growing Up Is Tough, takes a jab at bratty teenagers, the types who get turned loose too early in life, only to buckle from their newfound independence. However, it’s not the bills that spoil the good times of watchin’ R-rated movies (like Nell) and growin’ mustaches, but the evil Grither monster. Yes, a tiger-faced beast. The duo are Pee-wee Herman fans, and it shows as Tough highlights plenty of potty humor, puckish antics and a minute’s worth of masturbation. Their pratfalls are silly, but the pair shine in their singsong cadence, eloquently demonstrated in the satirical poem “The Symphony of the City” — an array of Manhattan stereotypes from union workers to the suspender-wearing dude who plays the sax on a fire escape. Campbell and Rust also have a flair for sophomoric shorts, but unfortunately the audience isn’t treated to them here. In Rust’s college documentary, Do You Know Lucinda?, the comedian stalks a girl he had a date with, a year later. It’s a poignant, vérité take on love lost. “Lucinda and I went on one great date, and then she wasn’t interested in seeing me again for no reason,” says Rust. “I received an e-mail from her parents demanding that I take the video off my Web site or they’d take legal action.” And that’s one to grow on. With Nick Wiger. Directed by Owen Burke. At the Upright Citizens Brigade Theater, 5919 Franklin Ave., Hlywd.; Wed., Aug. 9 & 23, 8 p.m.; $5. (323) 908-8702.