Tony de Mello has a variation of this, but here it is told as a Zen Buddhist story:
The Zen Master Hakuin (1686-1769) travelled extensively to learn from other masters. When he was 32 years old, he returned to the Shoin-ji, the temple in his home town of Hara, in present-day Shizuoka Prefecture. Here he devoted himself to teaching a growing number of disciples. Hakuin was praised by his neighbors as a teacher living an exemplary life.
A beautiful Japanese girl whose parents owned a food store lived near him. One day without warning, her parents discovered that she was pregnant.
This made her parents angry. The girl would not confess who the man was, but after much harassment, she named Hakuin as the father.
In great anger the parents went to the Zen Master and scolded him in front of all his students. All Hakuin would say was “Is that so?”
After the baby boy was born, it was entrusted to Hakuin’s care. By this time he had lost his reputation. His disciples have left him. However Hakuin was not disturbed, and enjoyed taking care of the little boy. He obtained milk and other essentials the boy needed from his neighbors.
A year later, the girl-mother couldn’t stand it any longer. She confessed the truth to her parents— that the real father of the boy was not Hakuin but a young man working in the local fishmarket.
The father and mother of the girl went to Hakuin at once. They asked his forgiveness and apologized profusely to get the boy back.
Although Hakuin loved the child as his own, he was willing. In giving up the boy, all he said was: “Is that so?”