The tensest moment of the reunion came when host Andy Cohen asked Ramona Singer about her divorce from husband Mario and their current relationship.
"Everyone in my family is doing well," Singer started, refusing to say anything further because of her daughter. "Mario and I are together … Let's go to someone else. Thanks, Andy."
When Cohen tried to push the discussion, Singer pushed back.
"So, how's your love life? Who are you going to have sex with tonight? Tell me."
"I'll tell you when I go on a reality show," he said.
"You're on a reality show," Singer retorted.
"I'm actually not, honey," Cohen zinged back.
That's when LuAnn de Lesseps inserted herself into the tense exchange, recalling how Singer had previously accused her and her ex of having an open relationship.
"It's hard when your other half cheats on you, Ramona."
"Don't even go there!" Singer yelled. "I want this closed down! Stop it, Andy. I don't want to talk about it."
"I'm done with Stonewall Jackson over here," Cohen said.
"Karma's a b––––," de Lesseps added.
The countess then set her sights on Sonja Morgan, whom she sniped with all season long.
"She just hasn't been a real friend to me," the countess said, stating Morgan didn't support her personally or professionally. "I don't trust you."
"I have friends sometimes I don't see them for two years," said Morgan. "I'm still their friend."
"It's obvious the friendship is fractured," Heather Thomson observed.
Carole Radziwill and Aviva Drescher revived their heated BookGate feud, in which Drescher implied that Radziwill had used a ghostwriter.
"I wrote my own draft [of my memoir], and then I hired a small village," said Drescher, who then implied that Harper Lee didn't write To Kill a Mockingbird. "Real writers use people to help them."
When Cohen asked Drescher if she was knowingly slandering Radziwill's career as an author, she said, "It seems like she was just protesting too much."
When Radziwill stated that this battle was not a typical Housewives fight over hair and dresses, but one that was bigger, and called Drescher's accusations and memories of their conversations "weird," Drescher exploded again.
"Use your vocabulary, writer-girl!" Drescher yelled. "You're not that important of a writer. Nobody gives a s--- who wrote your book!"
"I'm the host!" Cohen said, closing the book on BookGate.
Tune in for the final part of The Real Housewives of New York City reunion on Tuesday (9 p.m. ET) on Bravo.