New York- An Elmont man’s request for a “threesome” led to his getting his face slashed by the boyfriend of one of the women in his sexual fantasy, cops said.

The knife attack Sunday night inside the Jerk Hut Express restaurant in Elmont stemmed from a remark made hours earlier by Furman Walker, 18, and overheard by his attacker, Pierre Delpeche, police said.

Delpeche, 26, of Queens Village, was at his 18-year-old girlfriend’s Elmont home when the girlfriend was chatting on her cell phone with her pal Jackie Bellhumeur, also 18 and the girlfriend of Walker.

“The cell phone was very loud,” said Nassau Police Detective Lt. Robert Cuerbo, and it allowed the eavesdropping Delpeche to catch a few key words of a remark Walker made.

While his girlfriend was talking, Walker “yells in the background” to Bellhumeur to see if her friend “wanted to have a threesome,” according to Detective Robert Rispoli.

A flabbergasted Delpeche then quizzed his girlfriend about what he overheard.

“He hears something, but he’s not sure exactly what. So he asks his girlfriend and she tells him what [Walker] said,” Rispoli said.

Delpeche then allegedly told his girlfriend to call Bellhumeur back and to tell her “you don’t want to be friend’s anymore.”

A contrite Bellhumeur and her boyfriend later took a bus to Delpeche’s girlfriend’s house in an effort to make peace.

But Delpeche wanted none of it.

Police said Delpeche and an accomplice confronted Bellhumeur on Linden Blvd. and began pushing her, prompting Walker to beat Delpeche with his cane.

The accomplice then pulled out a handgun, sending Walker and Bellhumeur fleeing into the Jerk Hut pursued by Delpeche.

According to police, Delpeche, now wielding a large kitchen knife, beat Bellhumeur in the head with its handle, knocking her into the restaurant’s window.

He then turned on Walker, stabbing him twice, once in the nose and right cheek and again below the left ear.

Delpeche was arrested at 1:15 a.m. yesterday at a local hospital in Jamaica, Queens, where he had gone to get stitches for a cut below his eye.

He was charged with two counts of assault, cops said. Walker was listed in stable condition at a local hospital.