The cancer diagnosis of Vicki Gunvalson's boyfriend, Brooks Ayers, has been the main storyline of The Real Housewives of Orange County, and as expected, the issue was also brought up during the recently-filmed reunion special.

Brooks Ayers Posts Cancer Article After Claiming He Was Advised Not To Discuss The Matter

In a new sneak peek at the upcoming three-part special, fans get a glimpse of what they can expect to see when the ladies face off over the issue.

"I'm curious what's going to happen with Vicki," Heather Dubrow tells Bravo cameras as she prepared to go on set.

Meghan King Edmonds Wonders: Is Vicki Gunvalson 'Lying About The Cancer For Sympathy?'

"He's not sick. We are all agreeing on this. The only question to me is, when did you find out?" Dubrow later asks Gunvalson.

"I don't have any proof that he's not faking cancer, and I don't have proof that he is," Gunvalson responds.

Quickly, Shannon Beador jumps into the conversation, announcing she does have proof of Ayers' alleged cancer lies.

"I knew he was a piece of s**t from the day you started dating him, but now is your time to say, 'He lied to me,'" Barney then tells Gunvalson.

"I didn't lie about anything," Gunvalson says backstage, before adding, "Well, maybe a couple of lies."

For more of Vicki Gunvalson and her co-stars, tune into The Real Housewives of Orange County season 10 reunion, starting next Monday night, Oct. 19, at 9 p.m. on Bravo.

Tags: The Real Housewives of Orange County Bravo Reality TV Vicki Gunvalson brooks ayers