Most of us want to be a good person. But the difference between good and bad is often an arbitrary distinction, as comedian Nick Thune observes in his Seeso standup special, “Good Guy.” For instance, Thune reckons a bad guy buys his weed from a sketchy drug dealer, but a good guy lies to a doctor about nonexistent anxiety to get a medical marijuana card, because doing things the “legal” way eclipses the moral quandary. Thune is known to perform standup with an acoustic guitar, which adds an unexpected plaintive quality to his side-splitting observations. Catch Thune Thursday through Saturday, February 28 through March 2, at the Vermont Comedy Club in Burlington. Brittany Carney opens.