Billy Chenowith

Billy is Brenda's younger brother and Claire's new boyfriend, a good-looking art photography student who turns up charming, funny, and just a little too intense. He's magnetic in the way people who talk fast and feel everything can be — full of ideas, affection, and an unpredictable current running underneath.

Jeremy Sisto plays charisma as something faintly dangerous, letting warmth curdle into instability without ever tipping into cartoon. The writing uses him to needle the Fisher-Chenowith orbit's comfortable dysfunction, and Sisto keeps you off balance — you like him, you worry about him, and you're never quite sure which feeling is correct.