Robin L Marshall/Getty; Michael Kovac/Getty
On this week's episode of The Real Housewives of Beverly Hills, the group — sans Lisa Rinna — are all gearing up for Garcelle Beauvais' birthday party. But Diana brought the drama before the gathering even started, sending a text to everyone that she may not attend the party for personal and medical reasons following her miscarriage.
Diana then said that Garcelle, 55, might think she's "rude" if she doesn't come, despite her recent health issues, so she ultimately chose to show up.
Even though everything was off to an okay start, trouble soon followed as Sutton, 50, pulled Diana aside to check on her and hash things out. But Diana wasn't having it, telling Sutton not to "do phony s---" with her.
"I'm done being nice. We're done," Diana said in a confessional. "I'm ready for you to meet a different person."
Sutton was still trying to have an open and honest conversation, but the situation only digressed as that chat continued. It got to a point where the Georgia native commented on how Diana wasn't being "nice" to her.
"What? Should I yell, like you yelled at me? You know I'm Bosnian, I always respond well to yelling," Diana said sarcastically as Sutton replied, "Oh, yeah. I want to hear the Bosnian 'tough girl.' "
Diana then added: "What? Do you want me to butt head you?"
As Sutton tried to express her empathy once more for Diana's health, the newcomer suggested her castmate is "not sorry" at all.
"You're phony. You are the fakest person I've ever met in my life, literally," Diana said. "By the way, also, you're boring. I could forgive everything. I can't forgive being boring. You are really boring."
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
In an effort to try and mediate the situation, Kyle Richards and Garcelle eventually approached the two. But Diana was more interested in laying into Garcelle, asking the birthday girl: "What is the problem that you have with me?"
"I don't have a problem with you. You have a chip on your shoulder, it's got nothing to do with me," said Garcelle as Sutton chimed in, "This is a very different Diana. The bed rest did you good."
Garcelle then tried to get to the bottom of the tension boiling between Diana and Sutton at the event, leading the designer to explain how she had attempted to say she was sorry Diana had to endure a tough health matter. But Diana called out Sutton for giving a "fake" apology, next asking Garcelle if she was Sutton's "mouthpiece."
The actress, however, had enough of how "mean" Diana was being. "What you're not going to do is you're not going to mess up my birthday. So, goodnight. My kids are here, I'm not doing this," she said before walking off.
"I think we're done here," Sutton said to Diana. "You're an asshole."
Sutton then told her new enemy to "go back to your passive-aggressive ridiculousness," referring to her shady text calling out Garcelle.
As the two foes continued to go back and forth, the conversation returned to Diana's traumatic miscarriage experience. Sutton even said she empathized with her costar, but Diana didn't believe her.
Tommy Garcia/Bravo/NBCU Photo Bank via Getty
"How dare you question my empathy. That's all I have is empathy," Sutton said.
After Diana, again, rejected that claim, Sutton said: "You're a soulless person. That's a really mean thing to say."
"You need a new villain?" Diana asked. "Here I am."
The words "To Be Continued..." hit the screen before the episode officially concluded.
The Real Housewives of Beverly Hills airs at 8 p.m. ET on Bravo.