Ariana Madix, Tom Sandoval News: Did 'Vanderpump Rules' Star Cheat In Miami? [VIDEO]

According to Tom Sandoval's ex-girlfriend, he was unfaithful to Ariana Madix during a trip to Miami.

Lisa Vanderpump And Scheana Marie Dish On 'Vanderpump Rules' Season Three

Last night, on Vanderpump Rules' debut episode of season three, Kristen Doute was seen claiming Sandoval had hooked up with someone while on the east coast. Doute alleged she had confirmed the hookup happened using text messages and Instagram to verify the mystery woman was telling the truth.

“Tom went to Miami and cheated on Ariana," Doute announced to the cameras during Monday night's premiere episode, according to a Nov. 3 report by LALATE. "The Miami girl goes on social media and spills the news. I reach out to her on Instagram. The details are too specific to not be true. I have text messages between myself and this girl that Tom did in fact cheat.”

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Throughout the episode, Sandoval and Madix's relationship took center stage. After Doute delivered the information to Madix's best friend, Scheana Marie, Marie spoke to Madix, who didn't believe her boyfriend had been unfaithful. Then, the issue came up again. This time, at Scheana's birthday party.

At the bash, nearly every cast member, except Stassi Schroeder and Katie Maloney (who weren't at the party), got invovled. Sandoval confronted Doute, wanting to know why she was so obsessed with his life, and Jax Taylor told her it wasn't her place to make such accusations.

Speaking to Access Hollywood about the alleged cheating scandal on Monday, Lisa Vanderpump said, “You got to be watching closely. That’s a big story line.”

During an interview with Celebeat last month, Madix hinted that trouble was on its way.

"Unfortunately, you will probably see moments in our relationship that revolve around work and drama started by other people," Madix explained. "I doubt the funny stuff we do and talk about is interesting enough to be chosen over someone crying or throwing some kind of fit. In the trailer, I did see lots of kissing so that's cool! It's 'the season of the make out.'"

Vanderpump Rules airs on Monday nights at 9 p.m. on Bravo.