A 32-year-old man was stabbed to death in front of his girlfriend near a Brooklyn bus stop early Monday – by an unhinged attacker who seethed “What’re you looking at?” before lunging at him, police sources said.

The suspect, who has not been publicly identified, was acting erratic and knocking over scooters near the B38 bus stop at Lafayette Avenue and Malcolm X Boulevard at around 3:53 a.m. when he confronted the couple, according to cops and the sources.

Ryan Carson, of Bedford-Stuyvesant, was stabbed multiple times in the chest during the explosive encounter, essentially dying in his girlfriend’s arms, police and sources said.

The victim was taken by EMS to NYC Health + Hospitals/Kings County, but could not be saved, cops said.

Caution tape from the crime scene remained in place later in the morning as police investigated.

The brutal encounter took place across the street from a school.

Police did not immediately share a description of the suspect.