Mel B's former flame has claimed the star's explosive break-up with Stephen Belafonte was brought on by her father's death.
Christa Parker - who previously had a Lesbian fling with the 41-year-old beauty prior to her meeting her estranged husband in 2007 - says the loss of her dad Martin in March "hit her full force".
The 44-year-old businesswoman also said that Mel's nasty split from the 41-year-old filmmaker led to her reconciling her relationship with her mother Andrea, 61, and sister Danielle, 36, who she hadn't spoken to for several years because of their contentious relationship with the producer.
Christa told the Daily Mirror newspaper: "I think that her dad getting sick, the reality of that, and him passing - that hit her full force.
"She was always close to her mum ands sister and dad.
"She talked to her mum every day, she talked to her sister every day.
"Her mum would come to LA and we'd all go out and do things."
On how the family drifted apart when Stephen came into the picture, she continued: "But when her and Stephen got together that just didn't happen anymore. She got rid of her old friends, people that were close to her, because he had to be in control of everything.
"Her family despised him. Stephen would call Melanie's mum and sister and just cuss them out and abuse them He didn't like Melanie around them, so that's why she cut them off."
Mel's sister recently branded Stephen a "psychopath", days after her older sibling was granted a restraining order amid allegations her husband had been abusive throughout their 10-year marriage.
The former 'Emmerdale' actress wrote on Instagram: "Dear all media I won't be selling a story on my sister never have and never will!! Here is my comment below so you can now leave me and my mum alone and let us be united and grieve the loss of my dad.
"@stephenthinks11 8 years of abusive calls me and my mum have had stating we would never see Melanie again.I am laughing and celebrating as you were wrong.you are a sorry excuse of a man !! To the left to the left everything you own in the box to the left I hope you... go to jail and rot in hell !! #wifebeater #physcopath #animalkiller #abuser #eventslocker #moneylaundering #fraud #criminal #adultery #kidnap #attemptedmuder #firearm #controling #violent #evil #devilman #gotmysistersback #united #mydadisdancinginhisgrave #dontmesswiththebrowns (sic)"
In her restraining order, Mel - who has 10-year-old daughter Angel with Eddie Murphy and 18-year-old Phoenix with Jimmy Gulzar - claimed Stephen had hit her, got their nanny pregnant and forced her to take part in threesomes.
Stephen was recently granted monitored visitation rights with their fiver-year-old daughter Madison, amidst the divorce battle.