Vid shows kids joking after beat

Cops released surveillance video Tuesday of six teen suspects in the brutal assault of an off-duty firefighter who suffered five broken teeth after he tried to stop them from harassing a couple on the Upper East Side.

The video (below) shows the teens walking jubilantly down the street giggling and joking minutes after they allegedly jumped the 38-year-old firefighter on E. 86th St. near Third Ave. about 9:25 a.m. Saturday.

“He saw somebody in trouble and he thought he could help them, and now he’s suffering for it,” the firefighter’s distraught mom told the Daily News Tuesday.

The teens were taunting an elderly couple when the firefighter told them to knock it off. One of them sucker-punched the firefighter in the back of the head, knocking him facefirst to the ground, and kept hitting him.

The firefighter lost five teeth, suffered a concussion and needed 25 stitches to close a gash on his head. He was treated and released from a local hospital.

“He’s missing his teeth, and he’s got stitches all over his face — it’s not something a mother wants to see,” the victim’s mom said. “My husband was a firefighter, you know what to expect, but you don’t think something like this is going to happen, something senseless like this.”

“He was off-duty, but he was acting to keep the peace of New York City, which is his job,” she added. “Even though he’s hurt, I’m extremely proud of him. He was trying to help somebody else, and anybody would be proud of a son who did that. But my heart breaks to look at him.“

The suspects are described as three boys and three girls, ages 15 to 17.

Anyone with information is asked to call Crime Stoppers at (800) 577-TIPS. Calls are confidential.