'Vanderpump Rules' Cast Turns on Ariana Madix During Heated Finale

Ariana Madix is on the outs with her "Vanderpump Rules" castmates, and it's all thanks to her cheating ex-bf Tom Sandoval ... or, at least, her continued reaction to his cheating.

The season 11 finale for 'VPR' aired Tuesday and it took a shocking turn ... with Ariana's costars turning against her for refusing to accept an on-camera apology from Sandoval.

Instead, Ariana walked out on production ... yelling at the show's executive producer for Sandoval intervening in a conversation she was having with Scheana Shay.

The rest of the cast -- aside from Katie Maloney -- is standing against Ariana over her boundary about not filming with her ex, as they feel it's their job to have difficult conversations on camera.

Y'know, the whole "reality" part of reality TV!

Costar Lala Kent slammed Ariana in a confessional, accusing her of never fully being honest on the show. She added, "For Ariana to walk out this way, is just such a slap in the face."

Yet, as Ariana later pointed out ... Sandoval never tried to apologize off-camera, alleging he's simply trying to use her for a redemption arc of sorts.

Her theory was seemingly proven during a hot mic moment, where Sandoval gleefully declared the drama around Ariana was "good for me."

This heated finale comes a week after TMZ broke the news that 'VPR' would be taking a brief pause in production. The reason??? So the cast can breathe a bit in the wake of Scandoval.

It's the exact opposite of striking while the iron's hot, but perhaps needed ... based on the cast battle lines we saw last night.

Though Tuesday's episode certainly felt like a series finale ... we're told the show is not canceled.