And now more details are emerging about the couple's tumultuous - and allegedly abusive - relationship, thanks to court documents filed in the custody case.
In the papers, Patton, 41, claims that Thicke, 39, has been a long-time drug abuser, cheated on her shamelessly and even beat her on occasion.
But Thicke himself said that he believes the sudden custody fight stems from Patton's anger that she wasn't invited to his father,actor Alan Thicke's funeral in December.
But Patton's lawyer Larry Bakman says that his client legitimately fears for her life. In February 2014, Patton says Thicke exploded at her in front of their son and his nanny.
'I was in Vancouver filming a movie entitled Warcraft. Robin and Julian came to stay with me for the weekend. Robin told me that as part of my Valentine’s gift, he was going to wake up with Julian that day (which was an extraordinarily unusual action for him to take), so that I could sleep in.
'When Julian woke up that morning, the nanny brought him into our room. I asked him whether he was going to get up and watch our son, and Robin lost control. In front of our nanny and in front of Julian, he jumped out of bed naked, screaming. Julian was upset and frightened by this unexpected rage (as was I),' Patton said.
A few days after the Vancouver incident, the two decided to separate.
'Robin quite simply emotionally wore me down. I felt abused, disrespected and depressed. I wanted out of this marriage as I did not have the strength to go another day with Robin given the emotional cost,' she said.
Another issue that Patton brought up in the court documents was Thicke's shameless infidelity.
His wandering eye ruined her Valentine's Day in 2013, when Patton says he treated her to a stay at L.A.'s Chateau Marmont hotel. She says they rented two bungalows and that Thicke invited friends over to party. Later, she says they 'made love' in one of the bedrooms and she fell asleep.
But while she was asleep, Patton says Thicke tried to have sex with one of the other party attendants in another bedroom.
'When I confronted Robin about this, he admitted to attempting to have sex with the stranger, but stated that he ended up being unable to do so because of the amount of cocaine that he used that evening had caused him to be unable to perform … Julian was in another room with our nanny at the time,' Patton said.
Later that year, he went on tour, and when he returned Patton says her husband 'told me that he had unprotected sex with seven other women'.
'He then informed me that [a tabloid] had found out about this and that they were going to expose him. In exchange for better treatment, Robin offered them an exclusive interview.
'He wanted me to hear about the unprotected sex from him as opposed to reading it in the tabloids. I immediately had myself tested for sexually transmitted diseases and AIDS given his representation that his having sex with other women was unprotected,' she said.
Patton says she even caught him in the act once - after the MTV VMA's that same year.
After the taping of the awards show, I went to our room only to find Robin in bed with two naked women. I left the hotel, wandered the streets of New York and called my brother crying,' she said.
That was the same awards show that Miley Cyrus grinded up on Thicke for a performance of his hit Blurred lines. His inability to commit to one woman continued even after they separated.
In April 2014, Patton says that Thicke stated that he wanted to get back together and that he was making an album about her.
But on one visit home, on a break from filming in Vancouver, Thicke left his phone out and she glimpsed a text message to his friend Rich, asking him to come over to the house because he had 'six naked women' there.
I asked Robin about the text. He told me that he had sex with one of the girls in the guest bedroom. He told me that he had thrown a manicure and pedicure party for the six naked women in our family home.
'I told him that was the end. Robin agreed to a divorce and told me that he had very little money left and that he would most likely end up living in an apartment in the Valley,' Patton recalls.
In another incident, on the day before Christmas Eve in 2013, Patton says her husband accidentally called her while he was having sex with another woman.
'On another line, I called his band mates and begged them to reach him to tell him to hang up his phone, because the sounds of his sexual encounter were too much for me to bear,' she said.
Patton says that at first, they were co-parenting without issue. But she says she saw a change in both her son and her ex's behavior that caused her to file for sole custody.
Patton's main concerns started late last year, when her son told her that Thicke had started spanking him.
She says she first learned that her ex was using corporeal punishment on their child in December, when her son recalled an incident on a recent sleepover with his dad.
'Julian told me that while at the "old house", while spending the night with Robin, before going to sleep, Julian had asked Robin for one more hug.
Culled from Daily Mail