Ariana Madix Mourning Her Dog When Tom Sandoval, Raquel Leviss First Had Sex

Ariana Madix is not keeping quiet about how ugly the cheating scandal with her ex-Tom Sandoval and Raquel Leviss went down — revealing the cheaters first had sex in the car, while she was mourning the death of her dog.

In a preview clip of the season 10 finale of “Vanderpump Rules,” Ariana opens up about how she found out about the whole ‘Scandoval‘ for the very first time … and how the call went when she first confronted Raquel.

If you already thought things were bad, the story gets worse.

Ariana says, she first found a screen recording of them on FaceTime, and, “That’s when I called Raquel and I started, like, making her, like, fing tell me, ‘What the f? When did this start?'”

To her surprise, Raquel explained it had all started after a girls’ trip to Vegas last August — a trip Ariana left early because her dog Charlotte died.

To make matters worse, Ariana says Raquel still didn’t tell the whole truth — only confessing to kissing — but later Tom Schwartz revealed Sandoval and Raquel banged in the car.

She adds, “And he didn’t have a key to get in so he had to ring the doorbell and I had to let him in” … yikes!

As you know, it’s been a whole lot of drama involving the entire cast after TMZ broke the news Ariana had discovered the cheating was going on … blowing up her 10-year relationship with Sandoval.

The season finale is out Wednesday and it’s bound to be a wild ride.