Get ready to rumble.

In the first sneak peek of next week's Real Housewives of Beverly Hills reunion, things get nasty -- and tearful -- straightaway.

Camille Grammer opens up about discovering husband Kelsey's affair and defends herself against the haters -- and frenemy Kyle Richards. "This whole season was set up to make me look bad," Grammer bellows, adding that she's never lied.

(Kyle calls her "corrupt" for her porno past.)

Meanwhile, Kim Richards weeps as she calls sister Kyle a "bully," and opens up to Andy Cohen about a potential drinking problem.

Most shocking? Lisa Vanderpump's husband Ken's emotional tirade about a mysterious, unnamed enemy.

Watch the explosive clip now.