Is Lisa Vanderpump jealous of Taylor Armstrong's budding friendship with Kyle Richards?

In a clip from Thursday's episode of The Real Housewives of Beverly Hills, the fiery Brit tells Armstrong, 38, to "back off" from her onscreen BFF!

"Kyle and I have been friends for awhile and Taylor's trying to weave her way in there," Vanderpump complains.

But Armstrong, who has been seeking marital advice from Richards, 42, isn't backing down without a fight.

"I know you're jealous that we're bonding," Armstrong tells Vanderpump. "But I think Kyle's allowed to give support where support is due."

The Real Housewives of Beverly Hills airs Thursday at 9 p.m. (EST) on Bravo.