Luann de Lesseps is set to become a real housewife once again.

The Real Housewives of New York star is engaged to businessman Thomas D’Agostino, and the couple is planning a lavish New Year’s Eve ceremony in Palm Beach, Florida.

“You know what, it’s threefold,” Luann tells ET. “It’s Tom’s birthday, he’s going to be 50, it’s our wedding, and it’s New Year’s Eve.”

The reality star admits she’s still in the early planning stages -- locking down hotel rooms, a band, flowers, etc. -- but she does know one detail for sure.

“I’m going to do three different dresses!” Luann reveals. “For my big night, why not have three different dresses? I’m gonna work and collaborate and design one myself, because I love style and fashion. I’ve styled myself for the last eight years of the show.”

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

There is also one other thing Luann knows for sure: She’ll officially lose her Countess title once she ties the knot. Luann got to keep the designation following her divorce from French entrepreneur (and Count) Alexandre de Lesseps in 2009.

“That is true,” Luann admits. “I’ll be Mrs. D, Mrs. D’Agostino instead of Mrs. de Lesseps, and that’s OK.”

“It will always be a part of who I am,” Luann continues. “I have the Countess Collection on EVine, so I’m continuing with my brand … People are like, ‘We want to call you the Countess! We don’t want to call you Luann!’ I’m like, ‘You can always call me the Countess.’”

WATCH: Bethenny Frankel on Dating on Real Housewives of New York

Still, it seems like New Year’s Eve can’t come soon enough, as Luann couldn’t stop gushing over her man.

“I’m a hopeless romantic,” she admits. “I knew I wanted to get married again, I kind of put that out in the universe, and it came true. I’m just as shocked as you are. I’m shocked and thrilled.”

“When everything’s so easy, and this is your soulmate, life just glides along,” Luann shares. “No friction. It just works.”

Real Housewives Ramona Singer and Dorinda Medley previously told ET they were “shocked” by the relatively quick romance, a reaction Luann says she wasn’t surprised by.

“Some of them know Tom,” Luann says. “He’s the bachelor man about town. He’s never been married, and so, they are surprised ... nobody can believe it. They’re like, ‘What?! How can you get married after a month?’ Like I said, I married the Count after two weeks, we lasted 16 years and have two great kids.”

As for whether her castmates will be invited to the big day, Luann says that remains to be seen.

“Let’s see how the ladies behave at the reunion,” Luann jokes.

The Real Housewives of New York airs Wednesday nights at 9 p.m. ET on Bravo. For more from our chat with Luann, check out the video below.