Real Housewives of New York  newbie smacks down BF.

Kelly Killoren Bensimon, 40, the latest addition to the Bravo ‘reality’ show was arrested by NYPD after her BF 30-year-old Nicholas Stefanov called 911, telling cops she punched him.

According to the criminal complaint, Bensimon "hit him with a closed fist, thereby causing informant to suffer a laceration below informant’s left eye and substantial pain,"

The multi-hyphenate Benison, who is actually divorced, turned herself in and was later released on her own recognizance by police.

Bensimon’s attorney denied the charges, alleged that Stefanov is nothing more than "a jilted lover."

"If I hit her I’d be sitting in a jail right now," Stefanov said, revealing that the fought began over stuff couples fight over and that Bensimon "sucker- punched" him  but at least had "had the courtesy to take her [engagement] ring off first."

A Bravo rep said "We don’t comment on the personal lives of our talent."