Robin Thicke and Paula Patton are embroiled in a nasty custody battle — and the "Blurred Lines" singer is facing physical abuse allegations!

The couple, who divorced in 2015 after 10 years of marriage, share a son, Julian Fuego. Paula, 41, asked to limit Robin's joint custody after the six-year-old told school officials that his father spanked him multiple times.

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According to TMZ, the school reported the incident to the LA County Dept. of Children and Family Services, who opened an investigation against the Grammy-winning artist.

robin thicke paula patton

Paula then filed an emergency order, asking a judge to change Robin's visitation with their son to monitored daytime visits. However, her request was denied.

Robin, 39, defended himself against the allegations, writing in court documents, "On a very rare occasion and only as a last resort, I will use light spanking, but it is consistent with the law — open hand on the butt. This is the type of discipline to which Paula and I agreed during our marriage."

He then went on to claim that Paula is retaliating because she was not invited to his dad Alan Thicke's funeral last month.

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"Paula did not have a positive relationship with my father and often made negative comments to me about my father," he added. "As such, she was not welcome at his funeral."

robin thicke girlfriend

Robin with his girlfriend April and son Julian on vacation.

The DCFS investigation is still ongoing — and Robin will be interviewed tomorrow afternoon.

The news comes as a surprise to fans of the formerly friendly exes. In a recent interview, Paula revealed she was over her ex-husband and ready to find love again.

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"It didn't work out. It was a good time," she said. "Yes, I was very in love. …I am hoping to feel that way soon. But it feels amazing, so you got to get back up and give it a go again."

Meanwhile, Robin is dating 21-year-old girlfriend April Love Geary, even sparking marriage rumors with the brunette beauty last year.