'Housewives Happy Hour': 'RHONY' Star Luann de Lesseps Fires Back at Bethenny Frankel's Cheating Allegations

'The Real Housewives of New York' star tells ET her co-star is "one to talk."

Time to get off the Ramona-coaster and onto the Bethenny Frankel/Countess Luann de Lesseps Express on The Real Housewives of New York. Season eight promises multiple blowouts between the longtime co-stars -- and Luann gave ET her take on it all when she dropped by our studios for Housewives Happy Hour.

“With Bethenny and I, it’s always been up and down,” Luann admits.

At one point in the season trailer, Bethenny fires this line at Luann: “You have sex with younger men. You cheat, f**k younger guys, and criticize people about the same thing that you do.”

“She should talk,” the fashion designer scoffs. “She’s the one dating the married man … it was in the New York Post!”

Luann was referencing a February report from the outlet, which alleged the Skinnygirl mogul was pursuing a longtime friend’s husband. The article actually included a denial from sources close to the Skinnygirl mogul. ET’s sources also say the article has no merit, adding that Bethenny is currently 100 percent single.

Even so, Luann says Bethenny’s attack on her was out of line.

“The whole time, when she’s saying that to me, the whole time I was dating Tom,” Luann adds, referencing her now-fiancé, businessman Thomas D’Agostino.

“I didn’t tell the ladies I was dating Tom, because I didn’t want them to know exactly,” Luann continues. “I was keeping it private until I saw where it was going, and it went places very, very fast.”

WATCH: Housewives Happy Hour With RHONY Stars Ramona, Dorinda and Jules

Luann says we’ll get to see everything unfold on-screen this year, just like we have in the past.

“Bethenny and I … we’ve had our fair share of fights at fashion shows, at places in the Hamptons,” Luann recalls. “We have our ups and downs, and what I like about Bethenny is that, she lays it all out on the table, whether it’s true or not.”

“Whether I agree with her or not, at least it’s out there,” Luann tells ET. “It’s not, for the most part, behind your back. With me, she’s very upfront, and I give it right back to her.”

“I think a lot of women cower around Bethenny because they’re, like, scared of her,” Luann shares. “I never have been …  I mean, when Bethenny started the show, she had no money, no husband, no children, and I had it all.”

“She strived to get it all, and she got there,” Luann says. “I’m proud of her for that.”

Bethenny isn’t the only cast member Luann has drama with this season. There’s also tension between her and Carole Radziwill. Viewers will remember Luann got quite upset last season when Carole started dating chef Adam Kenworthy, whom she met through Luann. Adam previously dated Luann’s niece.

WATCH: Luann’s Real Housewives Co-Stars React to Her “Quick” Engagement

In the season trailer, we see Carole avoiding Luann -- a move the Countess calls “childish.”

“I mean, I apologized, she doesn’t want to accept it, and that’s not my problem,” Luann confesses. “I don’t live in the past. I’m not somebody who dwells on things, or carries grudges or hold things against people … Carole obviously likes to live in the past.”

Still, Luann promises there will be some resolution.

“You’re going to see Carole and I work on our relationship,” Luann says. “It does get better.”

See how Luann and Carole get to that better place by watching The Real Housewives of New York every Wednesday night at 9 p.m. ET/PT on Bravo. We at ET think it might just be the show’s best season yet -- watch the video below to find out why.