Luann de Lesseps once declared, “If you can’t be cool, you can’t be with the countess” … but Barbara Kavovit officially doesn’t care. Barbara broke her silence regarding the end of her friendship with the Real Housewives of New York City star exclusively on Us Weekly’s “Hot Hollywood” podcast.

“The narcissism of this woman, the self-importance and her blatant disregard for people that have helped her has got to stop,” Barbara declared on Wednesday, October 30. “Not only myself, but [our mutual friend] Anne and I’m sure Bethenny [Frankel], and even Mary, who does her makeup, we are disgusted with her. It’s just her total disregard for anyone else. I have no words for her anymore.”

While fans got a glimpse inside of Barbara and Luann’s friendship on season 11 of RHONY, the Heels of Steel author told Us that the two women were friends for nearly 15 years. According to Barbara, the “last straw” in their friendship was Luann’s comments about her on Jenny McCarthy’s SiriusXM show on Tuesday, October 29.

“Girlfriend, I can carry a tune, so hell with Barbara,” the “Feelin’ Jovani” singer said, referring to Barbara saying Luann is “no Adele” during a July episode of RHONY. “That’s the second time, also, that she got caught on camera talking smack about me. … You have to pull the weeds, so you can make room for the lowers.”

Barbara, for her part, was in disbelief by Luann’s remarks.

“That’s the thing with a narcissist, you can look at yourself and believe that everything about you is so wonderful and throw everyone away,” she told to Us. “I remember last year, picking her up off the floor, literally, trying to carry her, protect her. I was her protector for 14 years. … To make it like she’s pull weeds, like I was the bad person, like Bethenny was the bad person? … My prediction? She hasn’t hit rock bottom yet.”

She concluded: “There is no good with Luann. I had a 14-year friendship with her that I will walk away from forever. She will never have me as a friend again.”

For more from Barbara — including details of a scene filmed for RHONY season 12 — listen to this week’s “Hot Hollywood” podcast on Simplecast or iTunes.