Jennifer Lopez doesn't know if she'll return to Idol

As the final three prepare to face off on American Idol, there's no telling who will take home the title. But there's another mystery looming at the judges' table: will Jennifer Lopez return to the singing competition next season? "I don't know," Lopez, 42, says on Tuesday's The Ellen DeGeneres Show. If she makes her way back to sit with fellow judges Randy Jackson and Steven Tyler next year, it will be her third season on the show since Simon Cowell Kara DioGuardi and DeGeneres left in 2010. "I enjoy it. I really do enjoy it," she tells DeGeneres, adding, "I miss doing other things. It really does lock you down." Lopez, who took her relationship with boyfriend-of-six months Casper Smart, to the Idol stage last week, also points to her 4-year-old twins, Max David and Emme Maribel. "Now they're getting more mobile. They're about to go to school," she says. "I just don't know. I don't know."