Justin Bieber pens song about baby-claim fan Mariah Yeater

Musicians find inspiration in all sorts of places.

Justin Bieber told reporters Monday night at a listening event in London for his Believe album (out June 19) that he wrote a song dedicated to the 20-year-old fan who claimed to have had the singer's baby after a tryst with the pop star in a backstage bathroom. She later dropped a paternity case against him and admitted her ex-boyfriend was the child's father.

"Like that girl -- Mariah Yeater -- who said she was going to have my baby," he said, reports BBC Newsbeat. "I wrote about that situation."

Bieber added that he's not sure that song will make the album.

"We've recorded like 40 songs," he said. "Every song has a piece of me, it's hard to pick. I wrote almost all of them or co-wrote them."