A threesome in Brooklyn turned into a bloody attack after one of the people engaging in a ménage à trois pulled out a camera and started filming.

According to the New York Daily News, 20-year-old Manos Ikonomidis was fatally attacked with bats and knives on Monday. The other people involved in the act were an unidentified woman and 21-year-old Jack Doherty.

“It’s something out of a horror movie,” stunned building resident Carol Petersen, 37, said. “It’s horrible. It’s a nightmare.”

According to police, the threesome took place in Doherty’s apartment and the situation took a violent turn when one of the participants started filming and the woman became furious.

Ikonomidis’s girlfriend — who was not involved — received an ominous Instagram message reading “your boyfriend f**ked up and will be taken care of,” sources told NY Daily News.

A resident in the building said the woman involved in the threesome claimed she’d been raped. However, police said there’s no evidence disproving the act was consensual.

Doherty then drove the woman back to her Staten Island home, leaving Ikonomidis alone in the apartment. When Doherty returned, three additional men arrived moments after with baseball bats. Surveillance cameras recorded two white men and a black man chasing Ikonomidis with baseball bats as he tried to leave the building, sources said. Ikonomidis was beaten with bats and stabbed, the sources said.

Ikonomidis, bloody and weak, knocked on the door of Joy Liguori’s nearby apartment and collapsed.

“I saw the blood. It was out on the couch. That’s when I told him, ‘God, honey, you’re bleeding.’ He goes, ‘They stabbed me! They stabbed me twice! They stabbed me!’” Liguori told NY Daily News.

Ikonomidis was transferred to New York Methodist Hospital in Brooklyn, where he was pronounced dead at 4:33 a.m.

When Ikonomidis’s girlfriend arrived at the crime scene hours after the killing, she emotionally screamed.

“Oh, my God, no! My baby, it can’t be f**king real!” she cried. “[Why] didn’t you go home? Why didn’t you listen to me? ... He better go to f**king jail! You guys get him please? ... My baby, my baby, I love you so much.”