After mediator Whoopi Goldberg sent the show to a commercial break following an explosive moment between Behar and McCain, Behar reportedly blew up on producers about McCain, even threatening to leave the talk show.
"My God!" Behar reportedly yelled as her microphone was muted, a source told the Daily Mail. "Get this b— under control."
"If this s— doesn't stop I'm quitting this damn show. I can't take this much more," she allegedly said. Producers tried to deescalate the situation, but Behar wasn't finished.
"I've tolerated a lot of s— on this show but I'm at my wits' end with this entitled b—. Enough already! Enough already! I'm not playing nice any longer," Behar reportedly shouted, all in front of the studio audience.
McCain reportedly said, "I don't know why she's so upset. I just wanted her to focus on President Bush and not bring Trump into this for once."
The source said that the set was "frantic" after the blow-up.
"Everyone was frantic. The last thing they wanted was for Joy to walk off the show. She's done that before. Remember the Bill O'Reilly situation? She appeared just as disgusted as she did that day and they only had two minutes to contain this explosion on set and get everyone positioned to return for the next live segment," the source said. "It was utter chaos on set."
Behar's blow-up on McCain came during a segment that was meant to discuss the legacy of late President George H.W. Bush.
"As a candidate he said, 'Those who think we're powerless to do anything about the greenhouse effect are forgetting about the White House effect,'" Behar said, quoting Bush's 1988 speech. "And then he signed into law the Clean Air Act Amendments of 1990, one of the most sweeping environment statuses ever."
But Behar used the opportunity to transition into a criticism of President Donald Trump and her own personal politics.
"This president that we have now is trying to unravel everything that [Bush] did and Obama did," she said. "And if I ever become a one-issue voter, it will be about pollution and the greenhouse effect—"
But McCain cut her off: "Can we focus on the president [Bush], please? I don't want to talk about Trump when we're in the moment of — we're honoring a great president."
"Excuse me, a second please," Behar interjected. "I want to talk about the differences."
"But I'm not interested in your one-issue voter when a president just passed," McCain fired back.
"I don't care what you're interested in. I'm talking," Behar said.
"Well, I don't care what you're interested in either, Joy," McCain said before Goldberg threw the tense moment to a commercial.
Following the fight, the two women's relationship is reportedly "fine," a source told PEOPLE.
"They had a disagreement on-air, which is totally expected in that job," the source explained. "But they are both professionals. They seemed completely fine afterwards."
"They're two very different people, but they're both very professional," the insider added.
On an appearance of Watch What Happens Live with Andy Cohen, Behar previously addressed the notion that the co-hosts argue off-camera.1comments
"The idea that we're fighting backstage? Quite frankly, nobody has time to continue the fight afterwards," she said half-jokingly.
"The only time I wish I were a man is when you're a woman on a panel show," Behar continued. "Because men are allowed to fight and debate and get really heated and angry and there's an assumption that they're friends and they're smoking cigars and whatever. I'm there to debate and to fight. It's the point of the show, that we will have difference of opinion — it's called the frickin' View."