A 16-year-old boy was fatally shot in the head as he and his pal played with a gun inside a Bronx home early Monday, cops and sources said. 

John Nunez was found around 5:10 a.m. with a mortal gunshot wound to the head when police responded to the multi-family house on Prospect Avenue near East 169th Street in Morrisania, authorities said. 

Nunez, who lived just blocks away from the home, was pronounced dead at the scene by responding EMS workers, police said. 

The pair are believed to have been fooling around with the lethal weapon when it fired, according to law enforcement sources.

Nunez’s friend was taken into custody and charges were not immediately filed, the sources said. 

It was not immediately clear how the friends got a hold of the weapon.

Devastated women were seen sobbing and embracing at the scene of the deadly shooting Monday morning.