Justin Bieber Slapped With Paternity Lawsuit From 20-Year-Old Mariah Yeater (UPDATES)

We know what you're thinking: BEST 'STAR' COVER EVER.

The magazine's "world exclusive" could also spell the end of the Justin Bieber's career as a squeaky-clean teen dream. According to Radar Online, Star's sibling site, 20-year-old Mariah Yeater has filed a paternity lawsuit against the pop idol for allegedly fathering her 3-month-old son, Tristyn.

Yeater claims she met Bieber backstage after his concert at L.A.'s Staples Center on October 25, 2010; she was 19, and he was 16, so that eliminates the statutory rape argument.

"Immediately, it was obvious that we were mutually attracted to one another, and we began to kiss," Yeater alleges in the court docs, which get pretty graphic. "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."

She recounts: "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."

Camp Bieber denies everything. "While we haven't yet seen the lawsuit, it's sad that someone would fabricate malicious, defamatory, and demonstrably false claims," the singer's publicist says in a statement. "We will vigorously pursue all available legal remedies to defend and protect Justin against these allegations."

(Bieber's rep did not immediately respond to The Famous' requests for comment.)

If Yeater's suit has a shred of truth to it, this might be a career dealbreaker for The Biebs. Notes The Amplifier's Daniel Kreps in his post on the scandal:

Fathering a child at a young age isn't exactly a career killer -- Lil Wayne's first baby arrived when the rapper was just 15 -- but the tween market is insanely fickle when it comes to these things. The downfall of the Jonas Brothers could be traced back to when Joe Jonas started dating actress Ashley Greene (or was it Camilla Belle?), which broke the hearts of the millions of disillusioned fans who thought they actually had a chance with him. Something as benign as dumping Taylor Swift over the phone -- which Joe Jonas also did -- could be the difference between going gold and going platinum, so imagine the reaction of Bieber fans if they find out their idol sired a child after losing his virginity in an arena bathroom.

In an odd coincidence, Bieber rented out the Staples Center for a date with girlfriend Selena Gomez last month. They watched "Titanic."

UPDATE: In an oblique reference to the rumors, Bieber tweeted this Wednesday: "all the rumors...the gossip....Im gonna focus on the positives....the music." And this: "so Im going to ignore the rumors...and focus on what is real. an opportunity to help by doing what i love. Judge me on the music! Love yall!"

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