The uncle of a teenager charged in the death of Barnard College freshman Tessa Majors barked at cops “don’t get him f–king nothing” when the boy said he was thirsty during police questioning, it was revealed in court Tuesday.

Testifying at a pre-trial hearing in Manhattan Family Court Tuesday, police officer Kevin Garcia, one of the cops who busted 13-year-old Zyairr Davis in Majors’ Dec. 11 slaying, recounted his run-in with the boy’s uncle, Roosevelt Davis.

Garcia testified that police were interrogating Zyairr at the 26th Precinct station house on Dec. 12 when the teen asked for a drink, so Garcia ran to a vending machine to buy him Gatorade, the cop said.

That’s when he ran into Roosevelt Davis and explained he was getting the boy a drink.

That’s when the elder Davis told the cop “don’t get him f–king nothing,” Garcia testified.

Garcia and two other cops arrested Zayirr inside a building near the Morningside Park stairs where police said Majors was stabbed to death during a botched mugging.

Garcia and officer Randy Ramos Luna charged the teen with trespassing on Dec. 12 after recognizing his clothes from a grainy surveillance video from the night of the slaying.

The cops found a knife in Zyairr’s backpack, but have yet to identify it as the murder weapon.

Police have charged Zyairr and 14-year-old Rashaun Weaver — the alleged knife man arrested Saturday — with the slaying. Cops are working to tie a third teenager to the fatal attack.

Majors, a musician and aspiring journalist from Charlottesville, Virginia, fought back and bit her killer’s finger, police said. She crawled to the top of the stairs but died as a result of multiple stab wounds.

Her father, Inman Majors, a novelist and English professor, has attended all of the pre-trial hearing in Zyairr’s case but has not commented on the case — remaining silent again Tuesday.

The teen, who is being held at the Crossroads Juvenile Center in Brooklyn, is charged with second-degree murder and is due to go on trial next month.

It was unclear exactly why Roosevelt Davis denied the boy a drink, and he declined to comment as he left the courthouse Tuesday.