Justin Bieber, baby daddy? No way, he says, and he's willing to prove it: The pop idol will take a DNA test to show that he didn't father Mariah Yeater's child. Then he's going to sue her, sources tell TMZ. Yeater's lawyers apparently looked "nervous" when told of the Biebs' plan—which may explain why they haven't been returning calls. Team Bieber wants to sue to show the world that people can't just trump up nasty baby allegations against celebrities. Click for more details.