Source: Luann De Lesseps' Ex-Husband 'Sad' and 'Shocked' by Her Arrest

No one was more surprised by Luann de Lesseps' drunken arrest than her ex-husband, Tom D'Agostino.

The businessman had no idea the Real Housewives of New York City cast member was even back in Palm Beach, where they wed last New Year's Eve, a source close to him told PEOPLE Thursday.

The source said D'Agostino "felt really sad for Luann and her family that they had to go through this over the holidays," and was "shocked" that she was in town since she has "no ties" of her own to where they previously spent time together.

D'Agostino, 50, and de Lesseps, 52, married last December during an extravagant three-day celebration, but split in August and finalized their divorce in October.

The Bravo reality star was arrested late Saturday night after she and an unidentified male companion were caught trespassing in a hotel room they weren't registered to.

After "multiple attempts to get both subjects to leave over a five minute period," a security guard called for help, and two police officers responded to the scene, where they found the former Countess and her friend Julie Olson in the room.

While Olson left when asked, de Lesseps locked herself in the bathroom, and when the guard unlocked the door, she allegedly shoved a responding officer in the chest with her palm, then slammed the door on his face, "striking him in the forehead," according to police report.

After somehow escaping handcuffs in the back of a patrol car, de Lesseps reportedly tried to escape police custody, yelling, "I'm going to f---ing kill you" while police got her under control.

She continued telling the officers that she was going to "f---ing kill all of you" as she was brought to the station and booked into holding. She was released without bail Sunday morning after being charged in court on five counts, including battery of a law enforcement officer and resisting an officer with violence.

Later, the Countess apologized for her behavior, blaming it partially on bad memories of D'Agostino.

"I want to offer my sincere apologies to anyone I might have offended with my behavior," the Bravo cast member wrote. "This was my first time in Palm Beach since my wedding and being there brought up long-buried emotions. I am committed to a transformative and hopeful 2018."

Photo credit: Instagram/@snksounak