LOS ANGELES (AP) -- Did Justin Bieber have sex with a groupie after a Los Angeles concert last year? A woman has filed a paternity suit against him, saying he's the father of her son, born in July. Radar Online posted 20-year-old Mariah Yeater's lawsuit, in which she says Bieber has to be the father because she wasn't with anyone else at that time. She wants child support and a paternity test. Her lawyer says she's not looking for a huge amount of money. Bieber's spokeswoman says the suit is "demonstrably false" and they will fight it vigorously. Bieber himself tweets he's ignoring the rumors and he should be judged on his music.