Looks like Bethenny Frankel's New Year's Eve plans just opened up, as she won't be invited to Luann de Lessep's wedding
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Looks like Bethenny Frankel‘s New Year’s Eve plans just opened up.

After sparring with Luann de Lesseps throughout most of this season of The Real Housewives of New York City, the 45-year-old Skinnygirl mogul is officially off the guest list for de Lesseps’ upcoming New Year’s Eve nuptials to financé Tom D’Agostino, Jr.

“It’s hard to invite people that tried to do you harm,” de Lesseps exclusively tells PEOPLE of inviting Frankel to her wedding.

The 51-year-old Countess previously told PEOPLE she’d wait to decide which of her fellow Housewives would receive invites until after the season 8 reunion. But after its explosive filming, it looks like Frankel will be nowhere to be found among the 250 expected guests.

Perhaps presenting de Lesseps with evidence of D’Agostino, Jr.’s infidelity was the wrong decision for Frankel. The pictures – which showed D’Agostino, Jr. kissing a former Playboy model at New York’s Regency Hotel the day before his engagement party – caused an emotional scene during the Housewives’ Florida vacation.

“It was disgusting,” de Lesseps says of Frankel’s actions. “Her handling of the situation – and I go over this at the reunion – was terrible.”

For de Lesseps, Frankel crossed the line when she shared the news with Ramona Singer and Carole Radziwill before coming to the Countess directly – something she calls “the most brutal thing to do.”

“[They] don’t have my back,” she says. “She could have went to Dorinda, who introduced us, and said ‘Look I have this.’ [But] she was like the cat who got the canary. Does a good friend do that to you? Someone who has your best interest in mind? No.”

“It’s not authentic,” she continued. “It’s made for television. And that’s what she is.”

For more on Luann de Lesseps’ glam New Year’s Eve wedding plans and candid thoughts on her Real Housewives of New York cast mates, pick up this week’s issue of PEOPLE, on newsstands Friday

De Lesseps admits at first she was devastated by the news – which came just 10 days after her whirlwind engagement. But then she started to question Frankel’s motivations after learning Frankel had allegedly called the Regency Hotel to speak with its bartenders.

“It got very private investigative reporting for me,” she confesses. “Not only does she have a picture – she calls the hotel [and] she’s got this timestamp. And she digs and digs and digs for this information and then tells the other women without telling me?”

While she says she’s glad to have known about D’Agostino, Jr.’s slip-up, she would have preferred Frankel would have told her about the situation off-camera – “as a good friend would do.”

And she certainly thinks Frankel shouldn’t have tried to called D’Agostino, Jr. directly.

“She should’ve talked to me first,” says de Lesseps. “Not the other women, not tried to call Tom, but talk to me. I find that very bizarre. It’s terrible. That’s not somebody who has your best interest in mind – that’s someone who has their own agenda.”

So what exactly was Frankel’s agenda? “I think she’s just unhappy,” de Lesseps says. “As you can see throughout the series, she’s an unhappy person. If she’s not going after me, she’s going after Sonja, Dorinda and John, or Jules. It’s one person to the next.”

RELATED VIDEO: Countess Luann de Lesseps Spills All – Bethenny Frankel Drama, Wedding Details and Her Past With Her Ex!

As for Frankel’s claims that de Lesseps is walking down the aisle for attention, de Lesseps couldn’t disagree more.

“It’s my story to share,” she says. “Bethenny said I fell in love with the attention she’s spent her whole career getting. Who got married on TV? Who treated their husband like s— on TV? Who’s been trying to get divorced for longer than she’s been married? She’s the biggest media whore that ever lived. And she talks about me?”

De Lesseps also balks at rumors that D’Agostino, Jr. is not as wealthy as he appears – and dates rich women for their money.

“Tom’s richer than all of us put together – including Bethenny,” she says. “He has no interest in the fame or being with a Housewife. He fell in love with me, poor guy.”

The Real Housewives of New York City airs Wednesdays (9 p.m. ET) on Bravo.