Audrina Patridge Questions If Ex Justin Bobby Is 'Hooking Up' with Stephanie Pratt

“Everything comes out in Vegas.”

And that’s exactly what Audrina Patridge is hoping for in PEOPLE’s sneak peek of Monday night’s episode of The Hills: New Beginnings.

In the clip, the group heads to Sin City for a quick getaway, but they can’t seem to leave the drama behind them. While getting ready, Frankie Delgado asks Justin Bobby about the rumor that he’s been secretly hooking up with Stephanie Pratt behind Patridge’s back.

“I don’t see it in Audrina’s eyes that she wants to hang out with us because Stephanie’s around,” says Delgado, 38. “Even though they act like it’s all cool, there’s a little something there.”

“I don’t think that you’re doing anything wrong,” he adds.

But Bobby, 37, is maintaining his innocence.

“It’s not my problem,” he says of the tension between the women. “If I was f—– both of them then yeah, I’d be in a big predicament, but I’m not even kissing any of them.”

Back in Patridge’s room, she admits to Mischa Barton that she isn’t sure what to believe about the rumor.

“I feel like Stephanie and Justin are, like, being awkward and weird,” she says about Pratt and her ex. “Do you think that they’re hooking up?”

“Everything comes out in Vegas,” Barton, 33, responds, “so I think you’re going to find out right now if something’s up.”

The Hills: New Beginnings airs Mondays (10 p.m. ET) on MTV.