An off-duty police officer fatally shot a young man he suspected was having an affair with his wife, then turned the gun on himself, the New York Police Department has revealed.

The murder-suicide happened about 10:40 p.m. on Sunday, May 8 outside Buffalo Wild Wings restaurant on Route 211 in Wallkill, Orange County, New York the NYPD said in a Monday statement.

The NYPD statement revealed how Officer Sean Armstead, 36, took a sick day leave and tracked his wife and the man he believed was her lover, Edward Wilkins, 20, to the La Quinta hotel.

They left the hotel in separate cars, and Armstead tailed Wilkins’ vehicle — crashing into it at the Buffalo Wild Wings a short drive away, sources said.

The alleged boyfriend, a young man got out of the damaged vehicle and ran, but the officer chased him down and shot him in the head, then shot him again after he slumped to the ground, sources said.

Armstead then shot himself.His wife arrived at the bloody scene in a separate car and started wailinh, the statement said.

NYPD Officer Sean Armstead Gary DeYoung recounted that he was walking his dog when he heard the crash.

“Then one guy jumps out, comes over here and starts shooting away,” DeYoung told News 12.

“I was like, ‘Whoa.’ I called 911. By that time, there was two deceased on the ground here in the parking lot.”

Armstead, who lived in Port Jervis of New York, joined the NYPD in July 2011 and was assigned to a public housing command in the Bronx, authorities said.