Mariah Yeater: Woman, 20, Claims Justin Bieber Fathered Her Baby, Demands Paternity Test

Major OMG alert!

A 20-year-old California woman named Mariah Yeater has filed a lawsuit against Justin Bieber claiming he is the father of her three-month-old baby boy, reports Star magazine and RadarOnline.

According to court papers obtained by Star, the woman says she had sex with the teen pop star backstage at one of his concerts in Los Angeles on October 25 last year.

In the document, filed in a California court on October 31, Mariah Yeater wrote,

"After waiting for a short period of time with several young women, Justin Bieber appeared and engaged me in conversation,"

"Immediately, it was obvious that we were mutually attracted to one another, and we began to kiss. Shortly thereafter, Justin Bieber suggested that I go with him to a private place where we could be alone.

"I agreed to go with him and on the walk to a private area, he told me he wanted to make love to me and this was going to be his first time.

"After walking away from the other people backstage, Justin Bieber found a place where we could be alone -- a bathroom.

"We went inside and immediately his personality changed drastically. He began touching me and repeatedly said he wanted to f*ck the sh*t out of me. At the time I asked him to put a condom for protection, but he insisted that he did not want to.

"In his own words, he said that because it was his first time he wanted to feel everything."

Yeater is now demanding the 17-year-old teen pop star take a paternity test "to scientifically confirm" he is the father of the child.

Yeater also asks the court for Bieber "to provide adequate support for my baby."

Bieber's camp vehemently denies the woman's claims.