Keith Urban, 58, became visibly emotional while performing a song about an ex moving on at his Atlantic City concert on Friday. The performance of "We Go Back," a track from his latest album "Flow State," came shortly after his ex-wife Nicole Kidman was reportedly linked to private equity businessman Michael Reinstein.

During the show at the Hard Rock Hotel & Casino, Urban introduced the song by explaining its narrative about a man who regrets letting a past love go. "This song is about a guy and a girl growing up in a small town," Urban told the audience. "They were the first of their friends to fall in love. They had a good thing going, until the guy screwed it up... She tells him she's got somebody else."

The lyrics of the chorus, which Urban sang, include: "I know I never should have let you go. I was young and dumb, and I messed it all up bad. You tell me that it's too late now, 'cause there's somebody new around. But what we've got is the one thing you'll never have. We go back."

Following the ballad, Urban appeared to wipe away a tear as he looked out at the sold-out crowd. He then expressed his appreciation for the venue, saying, "This is why we keep coming back to Atlantic City."

Keith Urban became emotional at one point during the show as he crouched down on the stage and looked out at the crowd

The performance follows reports in July that Kidman was seen with Reinstein during a vacation in the Italian Riviera. A source close to Kidman told the Daily Mail that she "deserves to find happiness" after her past relationship struggles and that she has been trying to keep her family intact.

Kidman and Urban finalized their divorce in January, 19 years after their marriage. Reports of their separation first surfaced in September of the previous year. The couple's settlement agreement was reached shortly after the new year.

In a recent interview with British Vogue, Kidman spoke about her ability to adapt to life's unexpected turns. "I didn't expect this. I had a different view of what my life was going to be, but this is what it is now," she said. "You make all these plans and you have all these ideas of what it's all going to be like and then it's…not. You have to adjust. You adapt. The future, it's completely unknown to me right now."

She added that she has learned to move forward with hope, stating, "I can either really not confront it and just curl up, or I can just go forward with an enormous amount of hope."