Police arrested a woman Tuesday accused of fatally stabbing her mom’s sleeping boyfriend because her sister refused to hand over a soda, law enforcement sources said.

Burnette Singleton, 34, of Brooklyn has been charged with second-degree murder for allegedly knifing Russell Holdip, 54, in the face around 1:45 p.m. Sunday in the family’s Bedford-Stuyvesant apartment on Grant Avenue after getting into a fight into a fight with her sister, sources said.

Singleton – who authorities say is mentally unstable – initially went after her sister Sharlene Kelly with a knife over the drink, but Kelly managed to escape into her room, locking the door behind her, sources said.

Singleton took out her deadly wrath on her mom’s snoozing beau after she couldn’t get to Kelly. She fled home after the slaying, but cops were able to nab her.