He had a date with Destiny that went bad Tuesday, Suffolk police said.
The victim, a 30-year-old man from Huntington, answered an online ad from Destiny Sheperd, 21, of Central Islip and arranged a rendezvous for that night at the Rodeway Inn in Huntington Station, police said.
"It was their first time meeting," said Det. Sgt. Scott Welshimer of the Second Precinct.
But about 3:30 a.m., she called or texted three male friends who were nearby, he said.
"They come in, they threaten him and they take his money," Welshimer said.
They took $400 from him, and after the victim fled the room, he called police, Welshimer said.
The four were still in the room when officers arrived, the detective said: "I don't think they thought he was going to call the police."
Sheperd, of 81 Vanderbilt Ave., and her three friends were each charged with second-degree robbery and are expected to be arraigned Wednesday, police said. The three men are also from Central Islip: Timothy Clark, 21, of 9 Ash St.; and Gerone Garcia, 20, and Mario Malpica, 21, both of 6 Willow St.
Welshimer declined to name the website but said detectives are looking for similar ads there and anything else that is suspicious.
Online daters should be careful arranging face-to-face encounters, he said. "We recommend they meet people in public places, until they're sure who it is they're meeting, for their own safety."