Justin Bieber describes the paternity test he took after

Teen pop star Justin Bieber has described how he took a paternity test to prove that he is not the father of Mariah Yeater's baby. In an appearance on the Late Show with David Letterman, which airs in the US tonight, Justin jokes about the 'swab test' he recently took. The 17-year-old even referred to Mariah as a 'weasel'. He said: "I think I could smell a weasel a little bit. "It's pretty crazy how people make up false accusations. But I'm 17 - it's going to happen, being in the spotlight." Bieber, who is currently dating Disney star Selena Gomez, 19, dismissed the baby allegations, saying: "People can say whatever." When asked if he had taken the paternity test, the Canadian singer said: "Yeah, I took it." Asked if he had to take his clothes off, Bieber added: "No! They just swab your mouth." Mariah Yeater, 20, recently claimed that Justin is the father of her four-month-old son Tristyn. With the U Smile singer doing a swab test earlier this week.