Kim Richards and Lisa Vanderpump showdown. In a new a promo for "Real Housewives of Beverly Hills" season 4 Reunion - Part 2, Kim Richards challenges Lisa Vanderpump for exploiting her public fight with addiction.

According to RadarOnline.com, the talk starts when host Andy Cohen asks, "Why do you think [Kim] feels like you don't take her seriously?"

Lisa confesses that she just doesn't get her.

Sober Kim identifies her issues with Lisa. She admits that she doesn't believe that Lisa's concern about her, while she was fighting the addiction problems, is for real.

"Yes, I missed a whole lot, Lisa, and it wasn't just your party."

"I missed a huge chunk of my f---ing life and my children's lives, and I'm sorry if I missed a party or two," says Kim.

Lisa quickly defends herself and insists that she is upset by all the accusations and "never made a big deal" about Kim's absence.

However, Kim is not in a mood to stop. She accuses Lisa for not being there for any one of the contestants.

"You are full of s**t right now."

Meanwhile, Brandi Glanville posted a nasty tweet about Lisa Vanderpump. She attacked the British beauty with a one of the nastiest tweets so far.

"@LisaVanderpump could BBQ a baby and people would think it was cute," tweeted Brandi on Tuesday.

Lisa has not responded to the tweet, but her fans have started defending her on Twitter.

One of Lisa fans wrote to Brandi that she is jealous of her.

"WTF is wrong [with] you? Who tweets a comment like that? Disgusting!" tweeted another fan.

Another fan went on questioned Brandi's parenting and even urged to call The Division of Family and Children Services (DFCS). How will this tweet affect their chemistry on the show?

The next episode of "Real Housewives of Beverly Hills" season 4 Reunion - Part 2 airs on March 24.