Miley Cyrus and Kaitlynn Carter's Bikini-Filled Italian Getaway

"He has said on multiple occasions that he does sleep with other girls and she's okay with it," says Ashley Slack, Jason Wahler's wife.

Before Kaitlynn Carter hooked up with Miley Cyrus, she and Brody Jenner were already facing gossip they invited other women into their relationship by their "The Hills: New Beginnings" costars.

Monday's new episode began with Kaitlynn sitting with Whitney Port and Jason Wahler's wife Ashley Slack, opening up about her and Brody's decision to put having kids on hold, before addressing some of the rumors surrounding the couple.

"In the end, we've decided we really don't need to be in a rush," Carter said in a confessional, regarding children. "Honestly, I think it's better for me and Brody's relationship, taking that pressure away."

Shifting gears, she then told the other women, "I'm hearing people are talking about me and Brody and our personal life, saying we have an open relationship."

The talk originated from Stephanie Pratt, as Brody and Kaitlyn reacted to the "polyamorous relationship" claims over the phone to another friend in a flashback. "That's none of her business, we like what we like," said Brody.

"When Brody and I first were together, we were young, we were crazy, we were, like, you know, basically just trying to have the time of our lives," Carter said in a confessional. "So we did a lot of things in our relationship that, you know, I certainly wouldn't say I regret, but the level of gossip that I feel happens in the group -- it just makes me angry."

In her own confessional, Slack actually took Stephanie's side, saying the topic was fair game since Jenner himself brought it up in the first place.

"Brody's actually the one who said they had an open relationship on a national podcast," she said. "Does she really think people aren't going to gossip about that?"

On the other side was Port, who agreed with Carter. "I would not like people talking about my marriage behind my back, especially if I wasn't that close to them," she said in a confessional. "I think Brody and Kaitlynn's relationship is their business, how they want to portray it to everybody else, should be on their terms. Passing judgement on it, I think is immature."

Jenner brought up Pratt's claims later, after Brandon Thomas Lee staged a meeting between Brody and Stephanie to squash their ongoing beef. In an off-camera moment discussed in a previous episode, Brody exploded on Steph during a night out in Los Angeles, a moment that scared Spencer Pratt's sister.

Apologizing to Stephanie, Jenner said he had been going through a lot the week he went off on her, including fighting the Malibu fires. "That does not excuse the way I spoke to you and how I behaved that night," he told her.

"That was really really scary. you were jumping over furniture, you had two people holding you back," she replied, before Jenner then put some of the blame on her.

"I do think you can be in the center of a lot of drama and saying things, for instance, you brought up Kaitlynn and I's relationship, that we have an open relationship, that kind of stuff is really none of your business," he told her. "I find you find yourself in these situations where you are bringing up a lot of personal shit about other people."

"Brody, everyone knows," she ominously responded.

"I will say this, that night, I was in a very off place," he continued. "It was the very first night I had been out of the house, I drank, I was getting loose. It was the things I heard prior to seeing you that riled me up, a lot came out and I was very frustrated. This is what I heard and getting me riled up."

She relented, admitting it was probably "a terrible week" for Jenner, before he thanked her for being "understanding." He added, "I appreciate that. I never meant to scare you. I apologize."

The truce between Brody and Stephanie also led to Jenner smoothing things over with Spencer, who he's been on rocky ground with since the beginning of the season.

While Kaitlynn, Brody and Stephanie all seemed like they were done talking about the subject of open relationships, it came up one more time near the end of the hour, as Ashley had a convo with Whitney and Frankie Delgado's wife Jen.

Saying she was empathetic to their decision to hold off on having kids, Slack then added, "Brody gets away with so much. He has said on multiple occasions that he does sleep with other girls and she's okay with it. If she was having a baby with somebody that was still doing that, I'd be like are you okay with that?"

"The Hills" airs Mondays on MTV.