“[Chris] is grateful for the experience of collaborating with Lena, Judd [Apatow], and the entire ‘Girls’ cast and crew, but right now he’s working on numerous other projects and has decided not to return to the show.”
“The world that Lena wrote was very real, especially in New York,” he said. “But it wasn’t as relatable for me on a personal level. It’s not that I only like to play roles I know to a T, but there’s something satisfying about playing parts where you really relate to the characters.”
Source: Huffington Post