Keith Urban has reportedly been left in shock after seeing Nicole Kidman flirt up a storm with her co-star, Simon Baker.

Kidman and Baker star together in their new Amazon Prime TV show, Scarpetta, and their off-screen antics have sparked rumours that they’ve struck up a romance.

With the rumour mill in full force, Kidman’s ex, Keith Urban, is reportedly reeling, with an insider saying it’s “done a number” on him.

“Seeing Nicole and Simon holding hands was the equivalent of seeing his best mate with his missus, and it did a number on him,” an insider told Woman’s Day.

“He knew it was natural for her to lean on Simon – he was also there for Naomi Watts after her split from Liev [Schreiber]. The difference is, back then, Simon wasn’t single.

“Keith is hoping they’re just hamming it up for headlines, but even then, it feels to him like it’s a betrayal because both Nicole and Simon know how much even the hint of a romance between them will hurt him. He already suspected they were getting close while filming. This has become his worst nightmare.”

Kidman and Baker have known each other for decades.

“He hates that they’re giving interviews about how close they are,” our insider adds.

“He’s in total shock that she would flaunt a new relationship so soon after their divorce. It’s not what they agreed on for the sake of the girls.”

“Simon poses a real threat to Keith because the girls absolutely adore him,” added the insider.

Meanwhile, Kidman broke her silence about her split last week during an interview with Variety, where she said that she’s happy to be “moving forward”.

“I’m always going to be moving forward towards what’s good,” she said.

“What I’m grateful for is my family and keeping them as is and moving forward. That’s that. Everything else I don’t discuss out of respect. I am staying in a place of, ‘We are a family,’ and that’s what we’ll continue to be. My beautiful girls, my darlings, who are suddenly women.”

Elsewhere in the interview, the reporter asked Kidman if 2026 would be her year, while joking that “every year is probably the year of Nicole Kidman” given her wildly successful career.

“Well, not last year. I was quiet. I had other things going on. I was in my shell,” she revealed. “Now I’m in a place of saying, ‘2026. Here we go.’ I have [the sequel to] Practical Magic with Sandy [Bullock]. I’ll be in full witch mode.”