When Camille Grammer hosted a dinner party for her Real Housewives of Beverly Hills costars, there was only one thing on the menu: drama!

"You have achieved nothing in your life!" Grammer's friend, medium Allison Dubois, told a stunned Kyle Richards, 41.

As Dubois puffed away on a cigarette, Kyle lost her cool. "What are we, in elementary school?" she seethed. "This is all bulls*** to me!"

Grammer, 42, then jumped to the medium's defense, which prompted Kim Richards and Taylor Armstrong to rehash their own feud.

"All of a sudden I hear Kim and Taylor fighting again," Kyle said of the dinnertime squabble. "What is this, contagious?"

Adds Grammer: "It started out positive and it went down in flames."

The Real Housewives of Beverly Hills airs Thursday at 10 p.m. (EST) on Bravo.