Justin Bieber says he will take a paternity test to confirm that Mariah Yeater’s son isn’t his and that her story is completely made up as soon as he returns from Europe in two weeks. Justin’s lawyer, Howard Weitzman, has already found a lab to do the test. Once the test proves Justin isn’t the father, he plans to launch a lawsuit against her for defamation and libel. “It’s not that Justin or his attorneys expect to get a dime out of Yeater — she doesn’t really have any money — it’s just to send a message to people who might think about trying to pull a stunt like this on a famous celebrity in the future,” a close friend of Bieber’s said Sunday. Meanwhile, TMZ discovered that Yeater accused an ex-boyfriend of fathering the same child, and says that since hearing Bieber intends to sue, her lawyers appear “nervous” and are not returning calls.