'RHOSLC' Reunion: Mary Cosby Says She's Jen Shah's 'Trigger' (Exclusive)

Jen Shah and Mary Cosby face off at 'The Real Housewives of Salt Lake City' season 1 reunion.

The ladies of 'The Real Housewives of Salt Lake City' can't seem to agree if Jen Shah is triggered by Mary Cosby in ET's sneak peek.

"Jen, for a woman in her 50s you throw a lot of tantrums like a 5-year-old. What kind of example are you setting for your kids?" So writes a viewer into The Real Housewives of Salt Lake City's reunion, sparking a roller coaster of a conversation around Jen Shah's behavior in season one. First, Jen clarifies that she's not in her 50s, she's 48 (though she doesn't seem totally sure that's the right number), then she defends some of her more explosive moments (i.e. glass throwing, water splashing, yelling).

"I was going through a lot, and I wasn't proud of, you know, all the things I did," she offers the group, "or how I acted or communicated, but you know what? S**t happens when you're going through s**t."

Jen was dealing with the one-year anniversary of her father's death, a husband with too many work commitments and helping to take care of her aunt, who was recovering from a double leg amputation, at the start of the season. When host Andy Cohen asks Jen whether she's always been so "temperamental,"” she says "not like that." Then, Mary Cosby offers (somewhat out of nowhere), "I think she's more temperamental at me than anyone else, when my name comes, it’s a trigger."

Lisa Barlow attempts to shut down Mary's proposition, telling her, "When she gets upset when your name's said, it usually doesn't have anything to do with you. It’s like, 'Why are [sic] you keep bringing this up?' I don't think it’s directed at Mary."

"But hold on, Lisa," Mary fires back. "I said, like, why do you think Jen treats me the way she does? You said, 'I don't know. I'm confused why it’s every single time.' Those were your words. You remember that? You were in the car with your husband. And that's what I meant by, I spoke to Lisa on one occasion and I spoke to Meredith on a different one."

It seems that Mary is referring to her allegation that Lisa and bestie Meredith Marks told her they were afraid of Jen, but it's unclear. Lisa attempts to brush off Mary's claim by saying it was a "private conversation" (not that those can really occur in reality TV), while Meredith just looks around the room confused. See it all for yourself here: 

Mary isn't satisfied by Lisa's rebuff and opens up the conversation to the group. Whitney Rose says she agrees with Mary "100 percent," that her name triggers Jen, a statement that Whitney's cousin/Jen’s BFF Heather Gay seconds with an "absolutely."

"Mary herself doesn't trigger me," Jen says, saying it's just instances with Mary that caused her to pop off. Mary once again announces, "I trigger her."

"My first reunion was... it was very long, OK?" Jen told ET after taping the special sit-down. "Owning multiple businesses for years, you go through depositions, hearings, that’s just a natural thing as a business owner. The reunion -- I'm here to tell everybody -- the reunion was worse than, like, a nine-hour deposition."

"There's definitely some curveballs and some things that even I was surprised about at the reunion," she added. "If you thought season 1 was unexpected and explosive? You guys, wait for the reunion."

The Real Housewives of Salt Lake City's three-part reunion (a first for a freshman run!) kicks off with part one on Wednesday at 10 p.m. ET/PT on Bravo.