While Leakes and Williams have been close in the past, Williams was shocked when Leakes called for her to be fired on an appearance with Andy Cohen in which she called her former friend one of the "first to go" if she had her way.
When Leakes confronted Williams at Cynthia Bailey's birthday party for being cold to her in last week's episode, Leakes denied her firing comment and said she wouldn't discuss the issue.
This week, she brings the issue up with her family, who agrees Leakes' behavior was messed up.
"That right there is backstabbing at its best," Porsha says in a confessional.
She continues, "No more pain and no more drama. If that's what you're coming at me with, to the left."
Later, at Shamea Morton's bridal shower, Williams says she feels attacked by her best friend when she get called out for not buying a plane to her upcoming wedding in Africa.
"You supposed to be there," Morton says. "You supposed to be in the wedding. Figure that sh-t out."
Williams defends herself saying she has a health condition that prevents her from making that long flight, but castmate Kandi Burruss isn't buying it.
"I wish Porsha would just be honest and say she doesn't want to go, because she goes everywhere else she wants to go, medical condition and all," she says in a confessional.
The two take their fight to the parking lot, where Williams calls out Morton for bringing up their private business in front of the whole party.
"You're not a horrible friend but you're not the best friend," Morton says.
"I'm taking a break from friends," Williams says, driving away.
Real Housewives of Atlanta airs Sundays at 8 p.m. ET on Bravo.