The battered woman told the relative that suspect Asa Roberts, 18, forced her to swear on a Bible that she would not send the police after him.

“He took advantage of the fact that she was religious,” the relative told The News. “He made her swear on a Jewish Bible that she wouldn’t call the police, making fun of her.”

The victim was so terrified that she called the family member instead of the cops once the attacker left around 6:30 a.m. Tuesday.

“She even asked me afterward if she had broken her pledge, and I said, ‘No, you didn’t call the police. I called the police,’” the relative said. “I felt bad.”

Relatives said the old woman went out of her way to treat the suspect politely, asking about the teen’s family and at one point asking if she could make Roberts a meal.

“She treated him like a grandson, and then he raped her right before he left,” the relative said.