Mel B's former nanny, Lorraine Gilles, has filed a 128-page libel lawsuit against the star, in which she claims the singer acted as "cameraman" to film threesomes and only slept with the former Spice Girl's husband on her "instruction".
Lorraine Gilles has filed a 128-page libel lawsuit against the 'Too Much' hitmaker - who has daughters Phoenix, 18, and Angel, 10, from previous relationships and Madison, five, with Stephen - in which she hit back at the 42-year-old pop star's accusations she had an affair with the producer and aborted his baby.
In documents filed in California's Superior Court on Friday, Lorraine, 26, claimed she had sex "multiple times a week" with Mel over a seven-year period and only slept with Stephen on the singer's "instruction".
She stated: "My sexual and employment relationship with Melanie continued for approximately seven years until September 2016.
"During my time with Melanie, she and I had sex sporadically, sometimes having sex multiple times in a week.
"On the other hand I never had any sexual relations with Stephen without Melanie's instruction and without Melanie's actual or apparent consent. At no point did I represent to Melanie that I was pregnant with Stephen's child.
"The only times Stephen and I had sex was when Melanie instructed Stephen and I to do so. Or when Melanie herself invited her husband to join us in the bedroom, at which point Melanie would often serve as the 'camera man' and record the sexual encounter or take part in the menage a trois herself."
Lorraine insisted she felt "very uncomfortable" about being filmed and said in the documents she is concerned explicit footage she believes the couple have on their phones will be leaked online.
She wrote: "These recordings would be extremely embarrassing to me and my family... I do not want any of them to become public."
The former employee dismissed Mel's claims she had aborted Stephen's baby, insisting her pregnancy was the result of a one-night stand and the singer supported emotionally and financially through her through her decision to have a termination.
In the documents obtained by Mail Online, she stated: "Stephen and I never told Melanie I was pregnant with Stephen's child in 2014, as is stated in Melanie's declaration.
"Rather, I discovered I was pregnant several weeks after I went out for drinks with a friend at The Den in West Hollywood and had a one-night stand with a man I met at the bar. I immediately sought guidance from Melanie and spoke to her privately about the pregnancy. I felt comfortable approaching her because of our close relationship.
"At no point did I suggest or imply that I believed Stephen to be the potential father of the child. In fact, I had not had group sex with Stephen for several months prior to my unexpected pregnancy. Instead, Melanie herself assisted me with arranging a medical appointment, advanced the cash for the procedure, and booked a hotel for me to stay in to recover.
"On several occasions, Melanie actually visited me in the hotel and brought her children to make my recovery more pleasant."
Lorraine insisted she has had to take legal action in a bid to get Mel - who split from Stephen in March amid claims he had been abusive - to "leave [her] alone" and stop her "spreading lies", and claimed the 'Stop' hitmaker's actions had led to her being targeted by online trolls.
She wrote: "I have been actively trying to move past my time and relationship with Melanie. I simply wish that she shows me the same respect I've shown her over the past seven years.
"However this lawsuit became necessary after she refused to leave me alone and spread a number of lies about me and my relationship to her family on an international scale, all to benefit herself in her divorce proceedings.
"I have received countless messages, threats and insults from random persons all over the world, shaming and degrading me based on the false image of me created by Melanie."
Lorraine was given a $300,000 (approximately R3.3 billion) severance package when she was fired in September 2016 after getting "caught in the middle of intensifying marital arguments between the couple", but she denied Mel's previous claim they parted on bad terms, insisting that wasn't the case and she was even invited to an event at Madison's school after being dismissed.
She also received a handwritten apology note, which read: "I write this to say not only thank you for everything you have done for my kids, but also sorry."