A Manhattan woman thought she was luring a former lover to Long Island so her current boyfriend could rob and humiliate him, but she testified Thursday that instead he shot him to death.

Noriella Santos, 27, told jurors and state Supreme Court Justice William Condon an intricate story of love, deception, jealousy and revenge at the trial of Daniel Greenspan, 30, of Manhattan.

He is on trial in Riverhead, charged with second-degree murder in the Jan. 31, 2009, killing of Michael Sinclair, 32, of Brooklyn.

Santos, associate director of the Orphaned Starfish Foundation, which helps orphans and abused children, testified as part of a cooperation agreement with the Suffolk district attorney’s office. She also was initially charged with second-degree murder, but pleaded guilty to attempted robbery instead.

She said she met Greenspan in high school, when he was known by his birth name of Daniel Kraeger. He changed his last name to Rivera after they moved in together, but changed it back to Kraeger after Sinclair was killed and then to Greenspan.

They broke up for a time in 2008 and that summer she said she dated several other men, including Sinclair. But when she returned to school in the fall, she said she ended up back with Greenspan.

She also ended up with a case of herpes, she said, but didn’t tell Greenspan.

advertisement | advertise on newsday

“After the doctor told him he had it, I told him I had it as well,” she said during questioning by Assistant District Attorney Nancy Clifford.

Greenspan, furious, assumed the sexually transmitted disease came from Sinclair and became obsessed with him, Santos said.

Greenspan demanded that Santos lure him to Long Island, an unfamiliar place to Sinclair. Greenspan would then confront him, beat him and rob him, Santos said.

Santos said she reached out to Sinclair on Jan. 30, 2009. They went first to a club in Brooklyn and then drove out to West Babylon for a supposed party, she said.

Instead, she said they ended up on West Kellum Street.

“And the car stopped? And what happened then?” Clifford asked.

Instead of answering, Santos broke down in tears. After a short recess, she said they all got out and Greenspan and a friend of his, David Belton, approached with a gun and demanded Sinclair give him a chain.

“I don’t have a chain,” Sinclair said, according to Santos. Belton’s hand was shaking, so Greenspan grabbed the gun and shot Sinclair, Santos said.

After Sinclair was on the ground, she said Greenspan walked over and said, “Who’s the man now?” — and shot him in the face.

Even though she stuck to a planned story when Suffolk police found her and questioned her a few days later, she said Greenspan was angry about mistakes she made and hit her and put her in a darkened bathroom for hours.

advertisement | advertise on newsday

“He said that’s what jail was going to feel like,” she said.

Defense attorney Arthur Aidala of Brooklyn later moved for a mistrial, arguing that Santos’ testimony about Greenspan’s abuse was improperly prejudicial. Condon denied the motion, saying he struck much of that testimony from the record.

Aidala will cross-examine Santos on Monday.