Aaron Carter, currently starring in “The Fantasticks,” isn’t giving up pop music entirely. Backstreet Boy Nick Carter’s brother is working on a new album, his first since 2002. “My goal is to get it out by December, which probably won’t happen because I am being so critical on myself. I want the best,” he told us at the Cinema Society screening of “2 Days in New York.” Carter, who had a stint in rehab, added, “I am notorious for being a bad boy. I am more of a sophisticated one now, but I am still bad.” The title hasn’t been confirmed but may be “The After Party,” a reference to his 2000 “Aaron’s Party (Come Get It),” and is set to be full of “theme songs.”