With little to lose, they are eager to tell their stories: the mother, a once-faithful Catholic who says the church protected a philandering priest and treated her as a legal adversary, and the son, about what it was like to grow up knowing his absentee father was a priest.

“I’ve always called him Father Henry — never Father, never Dad,” said Nathan, at home between hospital visits. “I always felt he picked religion over me.”

The relationship between Ms. Bond and the priest is hardly unique. While the recent scandals involving the Roman Catholic Church have focused on the sexual abuse of children, experts say that incidences of priests who have violated sexual and emotional boundaries with adult women are far more common.