This should shock absolutely no one, but the ex-boyfriend of Mariah Yeater says she was lying when she made her claim that Justin Bieber was the father of her infant son. The ex also claims that Yeater hatched the story as part of a get-rich-quick scheme. Again, who's shocked? Not us!

RumorFix got the scoop from Robert Powell, who is behind bars. Powell said, "We were both homeless and living in Oceanside [Calif.] and Mariah was trying to make some quick money." He claims that Yeater, who said she had sex with Bieber in a Staples Center bathroom after one of his shows, devised the story and then sold it to a tabloid for $50,000. So much for fact-checking on the tab's part.

Powell also said that Yeater chose the Biebs for obvious reasons -- because "he was famous and all and thought she could get a lot of money by telling the magazine Justin was the father. She just saw him as an opportunity to make a lot of money."

He also disputed other facts in her story, saying that Yeater never attended a Biebs concert, much less met him. Powell also claims it is he who is Tristyn Yeater's father, even though the boy's birth certificate doesn't list a father.

"She said she was doing it for us … for our family and son," Powell, who is imprisoned on burglary and drug possession charges, said about Yeater's scheme. "She made it seem like it was all for us but she’s greedy. I don’t know, I still love her though. All I want is to be with my son, that’s all I care about. She can take all her money, I just want my son."

Powell also expressed sympathy for the Biebs, who is a victim along with Tristyn in this cash grab ploy, saying, "And man, on the real, I feel sorry for Justin Bieber. He’s just a little kid man. He don’t need to be going through all this drama. He got a career and s---t to focus on. I feel sorry for the dude."

Will the Mariah Yeater debacle ever go away? We hope so, so Bieber can keep doing his thing!