An FBI translator who was assigned to investigate a bloodthirsty ISIS terrorist wound up falling head-over-heels in love with the man — and married him instead, a report says.

Daniela Greene, 38, was apparently so lovestruck by the German-born jihadist that she left her husband in the US to be with him in war-torn Syria, and then lied to the feds about her whereabouts, according to CNN.

Denis Cuspert — a wannabe rapper-turned-ISIS pitchman — reportedly became the apple of her eye sometime in 2014, despite having a notorious penchant for violence.

He has been spotted showing off the terror group’s savagery in countless execution videos, some of which show him holding severed heads, CNN reports.

Roughly three years after joining the FBI as a linguist, Greene was assigned to the Detroit bureau in January 2014 and asked to probe Cuspert.

By June, she was already smitten with the tatted-up terrorist and making plans to be with him in the Middle East. They reportedly tied the knot in Syria sometime that month.

Greene eventually got cold feet, though, and decided to come back to the US in August 2014. She was immediately arrested upon her return.

According to CNN, Greene had been emailing an unidentified person back home about having second thoughts about her decision to pack up and leave soon after she got hitched.

“I was weak and didn’t know how to handle anything anymore,” she wrote in one message on July 8. “I really made a mess of things this time.”

Following her arrest, Greene agreed to cooperate with authorities. She pleaded guilty to making false statements involving international terrorism in December 2014 and was released from prison in August 2016 after serving a surprising two-year sentence.

Some have argued that Greene — who now works as a hostess in a hotel lounge — got off easy, compared to other Americans who’ve been prosecuted for ISIS-related crimes.

A Fordham University study from 2016 found that such people typically receive an average of 13½ years in prison.

While Greene’s conduct was described in court papers as skirting “a line dangerously close to other more serious charges,” Assistant US Attorney Thomas Gillice insisted that she receive a lighter sentence because of her cooperation.

But even Greene thought she’d be punished more severely.

“I will probably go to prison for a long time if I come back, but that is life,” she wrote in an email on July 22. “I wish I could turn back time some days.”

Greene reportedly told the FBI she was visiting loved ones in Munich, Germany, when she fled to Syria to be with Cuspert.

“Want to see my family,” she wrote in her Report of Foreign Travel form, before boarding an international flight on June 23, 2014.

But instead of visiting her relatives, Greene flew to Istanbul, Turkey, and then to the city of Gaziantep, just 20 miles from the Syrian border. From there, she met up with Cuspert and crossed into the country using the assistance of a third party, CNN reports.

In a statement, the FBI said it had taken “several steps in a variety of areas to identify and reduce security vulnerabilities” like the ones seen in Greene’s case.

“It’s a stunning embarrassment for the FBI, no doubt about it,” John Kirby, a former State Department official, told CNN.

Greene, who was born in Czechoslovakia and raised in Germany, had been married to a former US soldier before she fled to Syria.

She reportedly moved to the United states with him when she was younger and later attended Cameron University in Oklahoma, making the dean’s list along the way.

After earning a master’s degree in history from Clemson, she made her way to the FBI and eventually gained her top-secret national security clearance.

“I could see she was a really hard worker,” explained Clemson Professor Alan Grubb. “She was one of our better graduate students, I thought.”

Greene had been acting “in an investigative capacity” when she fell in love with Cuspert, CNN reports.

Court documents obtained by the outlet describe how she got acquainted with his online presence and rap persona — watching several of his graphic ISIS videos and following his accounts — in order to get a better understanding of who he was.

In one clip from July 2014, Cuspert can be seen “beating a corpse with a sandal” following the “bloody aftermath of the ISIS takeover of the Al-Sha’er gas fields in Homs,” according to a Middle East Media Research Institute report.

The ISIS savage, known as Abu Talha al-Almani in Syria, is infamous in Germany for his terror-related rap songs.

Performing under the name “Deso Dogg,” Cuspert once praised Osama bin Laden and rhymed about killing then-President Barack Obama.

Pentagon officials released a statement in October 2015 saying Cuspert had been killed in an airstrike, but later corrected the report and said he had survived.

Greene’s case is just now being reported after it was sealed by the Justice Department.

It wasn’t unsealed until after she was done cooperating with authorities, CNN reports.

“She was just a well-meaning person that got up in something way over her head,” said her lawyer, former assistant federal public defender Shawn Moore.