Joshua Malmgren, 30, of Lower Township, was arrested at the scene.
The accident happened around 9:20 p.m. Tuesday on Bayshore Road near the Green Creek Fire House in Middle Township.
The Cape May County prosecutor's office said an SUV struck the teens as they were walking along the shoulder.
Two cousins, Ashley Dauber, 13, and Nioami Lazicki-Gaston, 15, were pronounced dead at the scene.
Nioami's 14-year-old sister, Farrahanne, was also walking with victims but was not hurt.
"She got out of the way but, by the time she screamed out up ahead, this monster was already on top of them," said Nioami and Farrahanne's father, Bill.
Nioami called her mom at 9:10 p.m. to tell her they were on their way home. Then Farrahanne called eight minutes later to say there had been an accident.
"And then my other daughter called me at 9:18 to say they both got hit by a car," said their mother, Christina Lazicki-Gaston.
"That was the worst call a parent can ever get is that their children are lying dead."
Nioami and Farrahanne are from the area. Ashley had been visiting from Northeast Philadelphia.
The girls' parents say the driver robbed two young girls of their dreams.
"She just got into tech full-time. We were so proud of her. That was her main goal that she wanted to achieve was to get into tech. At least she had that before she left us," Bill Gaston said.
Malmgren was charged with two counts of 2nd-degree death by vehicular homicide, driving while intoxicated, reckless driving, failure to maintain a lane of travel and consumption of alcoholic beverage by an operator of a motor vehicle.
Malmgren was committed to the Cape May County Correctional Center in lieu of $50,000 cash bail.
The prosecutor said anyone convicted of a second-degree crime faces five to ten years in state prison.