Mary Cosby Accuses Heather Gay of Leaving 'Trails of Lies' in Explosive Fight

Things are not smoothing over for Heather Gay and Mary Cosby.

In PEOPLE's exclusive preview of the Wednesday, Oct. 23 episode of The Real Housewives of Salt Lake City, Cosby slams Gay by saying, "Everywhere you drop, and everywhere you stop, it's a lie."

The clip begins as Cosby enters Lisa Barlow and Britani Bateman's conversation and asks, "What are you guys talking about?"

"You, we were talking about you," Barlow tells her before Bateman tries to lighten the mood, "We were talking about how fabulous your outfit is."

Barlow then stops to ask Cosby if they are OK since she feels as if she was "jumping in" on her after the women went ziplining in last week's episode.

"This is just my thing, Lisa. Like if I get into it with somebody, you're automatically going to take that person's lie," Cosby says, referencing when Barlow defended Gay during their ziplining outing.

The preview then cuts to a clip of last week's episode during the moment when Barlow stood up for Gay after Cosby told her, "You champion body positivity, and now that's a lie too."

After viewers are taken back to the present, Barlow tells Cosby, "No, I felt for Heather in the moment, because I feel like you were bringing up stuff that, like, really hurt her."

Cosby's feelings haven't changed since the ziplining excursion. "It's not jiving with me that she's leaving trails of lies," says Cosby, to which Barlow responded, "But I think she felt hurt. And she was trying to express that to you."

Once Gay enters the conversation, Barlow tells her what's going on, and Cosby directly tells her, "Everywhere you drop, and everywhere you stop, it's a lie."

Gay gets visibly angry and repeatedly tells Cosby, "That's extremely hurtful," and "Don't you f--ing tell me when I've lie."

"Don't you dare, don't you dare," Cosby replies.

"So if I tell you the truth, facts of you on you, you say it's a lie," says Gay. "Don't push me, I've been a good friend to you."

Cosby replies, "Don't push me. You're a liar. Ask God who's a liar."

"God knows," says Gay.

"Yeah he does know. And he knows all about you," Cosby adds.

As Barlow tries to break their verbal argument, Cosby continues further, telling Gay, "Whatever I say behind your back, I say it to your face."

"That's not honorable. To say horrible, mean things to my face, did I do that?" asks Gay, prompting Cosby to ask before the clip comes to an end, "Name a time that you've been good to me?"