"Brooks would do something terrible when my mom was on the other side of the room or in a different room," Culberson alleges. "He hit on me when I was pregnant at [my mom's] birthday party, and I told her that he did it, and she called me a liar and said that he would never want me."
Gunvalson sits in silence while her daughter talks -- until host Andy Cohen asks Gunvalson if she believes Culberson's claims.
"I have to believe it," Gunvalson says. "My daughter said it."
That's when Gunvalson's longtime friend, Tamra Judge, pushes Culberson to share more, exclaiming, "He wanted to show you his dick!"
"He wanted to show me his ween-ween," Culberson claims. "He told me it was really big and that his nickname was 'Girth Brooks.'"
Gunvalson sits stone-faced as co-star Meghan King Edmonds' mouth drops open, and she whispers, "That's messed up."
Culberson has a long history of not liking Ayers, confronting him in 2013 after he was caught on tape telling Culberson's husband it's OK to beat her. Culberson even refused to stay in the home Gunvalson and Ayers shared when visiting California.
That's no longer an issue, though. Ayers and Gunvalson broke up in August, following months of speculation by Gunvalson's co-stars that Ayers is faking cancer. Ayers has denied those claims, and maintains he is battling the disease.
Check out the video below to learn more about Gunvalson and Ayers' breakup.