Justin Bieber's Baby Accuser
Not Her First
'You're The Daddy' Allegation
The woman who claims Justin Bieber fathered her child made the exact same allegation to her ex-boyfriend last year ... this according to her ex-BF's grandmother.
TMZ spoke with Frances Lippe ... who tells us Mariah Yeater had been dating her grandson John Terranova in Las Vegas toward the end of high school.
Lippe says Yeater came to their home in December 2010 and told Terranova she was pregnant with his child. He insisted he did not get her pregnant.
The two got into an argument and police were called ... because Yeater allegedly broke a car window out of rage.
Later that day, according to the police report, Yeater returned to the home to work out a payment plan for the window ... and got into another altercation with Terranova ... and allegedly slapped John 3 separate times in the face with her open right hand.
Yeater was arrested and charged for battery. A court date has been set in Vegas.
Lippe tells us after the altercation, they never heard from Yeater again.
We've made multiple calls to Yeater's attorneys -- so far, no response.