"LeAnn Doesn't Want Eddie Around Me," Says Ex Brandi Glanville

Although custodial boundaries are in place, Glanville says her ex-hubby's new girlfriend is keeping her from her son's birthday party

So much for the whole "working together" as parents thing.

Eddie Cibrian's ex-wife, Brandi Glanville, tells E! News exclusively that while the two are attempting to work through their impending divorce amicably, her former hubby's new girlfriend, LeAnn Rimes, is putting quite the damper on things—starting with their son Jake's birthday festivities in April.

"Eddie and I had planned to do something together and small for Jake's upcoming birthday on April 15th," Glanville tells us, but unfortunately, "[Eddie] has changed his mind. He is now saying I can't see Jake on his birthday because it falls on his custodial day and it would make LeAnn uncomfortable."

Glanville understands that assigned custodial days are in place for a reason, but tells E! News she's been more than accommodating of the couple's needs in the past, and simply asks for the same in return.

"I have been so cooperative with Eddie and LeAnn for the sake of my children," says Glanville.  "I even went and signed and notarized a document saying they could take my kids out of the country to Mexico on vacation. I wouldn't want to deprive them of such a great opportunity."

Glanville tells us her frustrations with her son's birthday are just the tip of the iceberg. "I have already spent Christmas Eve and Christmas morning alone, missing my children, and crying because I have no family nearby," she says. "Jake is my son, not LeAnn's. He should be with both his parents on his birthday."

And while she says she'll do whatever she can to be there on for her son's celebration ("I don't care if LeAnn is sitting next to me when Jake blows out his candles. I will be there."), her legal team tells her she should concede.

"Eddie seems to care more about LeAnn than what is best for our kids," Glanville says of her thoughts on her ex's new priorities. "He doesn't even come to Mason's baseball games on my days because LeAnn doesn't want him around me."