Once the epitome of Hollywood romance with their affectionate appearances, Nicole Kidman and Keith Urban’s fiery relationship has simmered down recently, insiders say.

Following Monday’s revelation by the Daily Mail that Kidman, 58, and Urban, 57, have startlingly parted ways after nearly two decades together and having two children, sources point to a deficiency in intimacy and their hectic lives as the major culprits behind the breakup.

‘Keith never sees Nicole, either she is filming or he is on tour,’ one source tells the Daily Mail.

‘There was genuine love, and a divorce isn’t certain. With their history, reconciliation remains possible, but currently, they aren’t functioning as a couple,’ a source elaborated.

It appears Urban initiated the separation, driven by dissatisfaction within the marriage, prompting him to voice his concerns. Kidman reportedly was taken aback by her husband’s actions.

Ubran’s main complaint appears to have been an increased coldness between the couple.

‘Their connection lacks intimacy; they’re simply going through the motions of being married. If this pause rekindles their bond, that would be wonderful, but Keith felt compelled to express his discontent,’ the source added.

‘She was blindsided, but we shall see how things go during the holiday season and his upcoming birthday [next month]. They have some work to do.’

The Daily Mail reached out to representatives for the pair who have been unavailable for comment.

Kidman and Urban share daughters Sunday Rose, 17, and Faith Margaret, 14.

Meanwhile, a source close to Kidman notes she has been primarily caring for the children and maintaining family unity during this challenging phase, as Urban has been absent.

The country star has been on his High and Alive World Tour since May. He is due to perform in Hershey, Pennsylvania on Thursday.

Kidman and the children, meanwhile, have been living in a stately London home.

The actress has been staying in England to film the sequel to her 1998 movie Practical Magic and has been paying a reported £65,000 ($87,000) each month to stay in a luxurious Hampstead mansion once owned by pop star Boy George.

While the London move was for work, it has certainly raised eyebrows back in Kidman’s native Australia.

‘[Kidman and Urban] do make an effort to speak every day when they’re apart, but it is shocking how much time they’ve spent apart since Nicole’s mother died last September,’ an insider told local magazine Woman’s Day earlier this month.

‘It’s like they both went their separate ways. Now she’s getting comfortable in a dream home in London on the other side of the world.’

In July, Urban dropped a hint that all was not well between the pair when he dramatically hung up during a phone interview with a radio station after a crude question about Kidman’s raunchy recent scenes, such as in her movies Babygirl and A Family Affair.

For her part, and while promoting her Netflix series The Perfect Couple back in September last year, Kidman admitted there was no such thing as a ‘perfect’ marriage.

‘There’s no perfect anything,’ she said, ‘anything that’s presented as perfect… forget it.’

Kidman was previously married to actor Tom Cruise for 11 years from 1990 to 2001. They adopted two children together.