It’s official: LeAnn Rimes and Eddie Cibrian are no longer hiding their relationship. On Saturday night, the couple stepped out to the Kings of Leon concert in Los Angeles, just two days after they hit the links – and openly flirted with each other – at Valencia Country Club.

The couple’s decision to go public prompted Cibrian’s estranged wife Brandi Glanville to tell PEOPLE: “He’s just somebody I don’t know.” In March, she had stood by her husband of eight years after allegations surfaced that Cibrian, 36, and Rimes, 26, were having affair.

“I don’t understand,” she says now. “You think you know one thing and you wake up and it’s all been a lie.”

Glanville, who is separated from the CSI: Miami star, says she is unable to completely explain to the couple’s sons Mason, 6, and Jake, 2, what is going on between mom and dad. (Rimes and her husband, Dean Sheremet, are also separated.)

“They know that daddy is at work all the time,” she says. “That’s what I tell them. When he does come home it is surprising for them and they are very happy.”

Glanville, on the other hand, has a different reaction: “I’m just like, ‘You know what? You’re not the man I married.’ “

She adds that she has spoken with Rimes twice recently, and told her, “‘He’s all yours.’ “

Glanville says she has no plans to reconcile with Cibrian, and hopes to file divorce papers soon. “There is one side of him that I absolutely love and always will,” she notes, “but that side of him is not the side I’m divorcing.”

Neither Cibrian’s nor Rimes’s rep was available for comment.