When the whole assembly is ready, they are married by the commissary.
Linkerton treats his relations to champagne, but soon the festival is interrupted by the dismal howls of Butterfly's uncle, the Bonze, who climbs the hill and tells the relations, that the wretched bride has denied her faith, and has been to the mission-house, to adopt her husband's religion.
All turn from her with horror and curse her. But Linkerton consoles his weeping wife and the act closes with a charming love duet.
The second act shows Butterfly alone.—Linkerton has left her, and she sits dreamily with her faithful maid Suzuki, who vainly invokes her gods, to bring back the faithless husband.
The young wife, who has been waiting three long years for his return, still firmly believes his promise, to come back when the robin-redbreast should build its nest.
She refuses a proposal of marriage from prince Yamadori, who has loved her for years, and now tries again to win the forsaken wife. She answers him with quiet dignity, that, though by Japanese law a wife is considered free, as soon as her husband has left her, she considers herself bound by the laws of her husband's country, and Yamadori leaves her.
Sharpless now enters with a letter he has received from Linkerton. Not daring, to let her know its contents at once, he warns her, that her husband will never return and advises her to accept prince Yamadori's offer.
Butterfly is at first startled and alarmed, but soon she recovers herself, and beckoning to Suzuki, she shows Sharpless her little fair haired, blue eyed boy, begging the Consul to write and tell her husband, that his child is awaiting him.
Sharpless takes leave of her deeply touched and without having shown the letter, when Suzuki enters screaming and accusing Goro, who has goaded her to fury, by spreading a report in the town, that the child's father is not known.