See Brittany Cartwright Finally Lose It in Dramatic Vanderpump Rules Sneak Peek

Exclusive! Find out what pushes the reality star to the edge

Brittany Cartwright has had it. The famously cool Vanderpump Rules star confronted her pals and finally snapped in the clip below.

"I just feel like people are waiting for me and Jax to mess up or that I'm hiding something, that we're not as good as we are," Brittany says in a confessional about her relationship with Jax Taylor. "When are people going to believe that we are happy?"

She's sick of it.

In the scene, Katie Maloney-Schwartz brings up Jax, which sparks Brittany's outburst. "I'm already on the brim of freaking out," she says tearfully after leaving. "It's not gonna be, like, my relationship is, like f—ked."

After Brittany storms out, the other Pump Rules stars try to dissect what that was all about. "She just, she lets very little things affect her in a big way," Scheana Marie says.

She's so upset, Jax checks in with the ladies.

"Sounds like it could be some relationship s—t. I mean, I would feel this way if I was marrying Jax," Katie says,

Vanderpump Rules airs Monday, 9 p.m. on Bravo.

(E! and Bravo are both part of the NBCUniversal family.)