Chrishell Stause's disdain for 'Traitors' costar Tom Sandoval is not just for the cameras ... telling us their beef is putting the real in reality TV.

We caught up with the "Selling Sunset" star at LAX, where she spilled all on filming season 3 of the Peacock competition series ... including her callout of the "Vanderpump Rules" alum early on in the season.

As she puts it ... Tom is not her "favorite," which is the nice-girl way of saying she pretty much hates the guy.

For those who don't watch the show, Chrishell accused Tom of being a traitor early on in the competition ... after she felt the Bravo personality targeted her for being good friends with his ex, Ariana Madix.

She later confessed on "Watch What Happens Live" to leaving him out of her recent "Traitors" tribute post on Instagram ... bluntly saying "I hate him."

However, as Chrishell tells us ... Tom isn't a fan of hers, either -- noting the lack of love "goes both ways." So, it's clear she isn't losing sleep over their drama.

Chrishell says she loved plenty of other cast members, though ... shouting out "The Bambis" -- an alliance made up of herself, Nikki Bella, and Gabby Windey -- and Dylan Efron, Zac Efron's equally hot brother.

So, it's not all bad vibes in the castle!!!