Vicki Gunvalson finally admitted what the ladies of "The Real Housewives of Orange County" have believed all season: that her ex-boyfriend Brooks Ayers faked his cancer diagnosis. Gunvalson came clean to her friends and her daughter on part three of the "RHOC" season 10 reunion special.

After defending Ayers all season long from her friends' accusations that he was lying about having stage three Non-Hodgkin's lymphoma, Gunvalson spoke honestly about the issue for the first time on camera.

"I don't have any definitive documentation that he doesn't have cancer..." she started, before she was interrupted.

"What does your gut tell you?" Tamra Judge, Gunvalson's friend and "RHOC" cast mate asked.

"My gut says he doesn't have it," Gunvalson said quickly, and a dead silence fell over the reunion set.

Then Gunvalson's cast mates all jumped in, and Judge asked Gunvalson when she finally figured out the truth. Gunvalson said she only realized he was lying three months ago.

Reunion host Andy Cohen noted that Gunvalson seemed disconnected and asked if it was because she took a Xanax before filming, but her daughter Briana Culberson jumped to her mother's defense.

"I really think she's starting to freak out about what he's done to her life and all of the relationships that have been messed up because of this guy, Culberson said. "I think you're like in a huge state of shock."

"Because nobody wants to feel duped or be taken advantage of," Gunvalson said, choking back tears. "I'm sad, but I'm relieved that I'm not with this man anymore, and I got a lot of pieces to pick up a little bit. I learned a lot, and I got duped."

Watch a clip from part three of the "RHOC" reunion special here.