Unlikely Allies: Kyle Richards & Brandi Glanville Are Becoming BFF's

In the fallout of Brandi Glanville and Lisa Vanderpump's recent spat, Eddie Cibrian's ex-wife has become very chummy with one-time frenemy Kyle Richards, RadarOnline.com is exclusively reporting.

Vanderpump and Glanville got into an epic fight while filming the Real Housewives of Beverly Hills in Puerto Rico, when cameras captured Yolanda Foster confronting Lisa about allegations that the British beauty was a back-stabbing friend.

Brandi backed David Foster's wife, putting a major ripple in her once-tight bond with Lisa.

"Brandi revealed that Lisa had told her to take magazine articles about Kyle Richards' hubby Mauricio Umansky cheating on her on a trip the ladies took several weeks earlier to Palm Springs," the source previously told us.

Paris Hilton's aunt & Glanville, "have become a lot closer after the Puerto Rico incident," a show insider told us. "The two have been spending time together.

"Brandi felt bad for her role in going after Kyle about her husband allegedly cheating on her. She had gone through hell when her hubby, Eddie Cibrian hooked up with LeAnn Rimes while they were still married. Kyle has been very receptive to Brandi."

Kyle and Lisa "had been attempting to mend fences before the Puerto Rico trip, but Brandi's revelation was a slap in the face to her," the source added. "She has since stopped talking to Lisa because she is just so disappointed in her one-time friend."