Pinkerton's Intentions (Dramatic Irony)
In the first scene, Pinkerton makes it quite clear that he wants to marry Butterfly only for a short time. The house that he has procured—as well as his marriage—are all conditional, as contracts in Japan are much looser than in America. Thus, even though Butterfly does not know how loosely Pinkerton is taking their marriage, the audience does, which creates a dramatic irony in which we know she is in danger before she does.
Warnings come true (Situational Irony)
Indeed, Butterfly is not completely in the dark, as many people try and warn her about the potential for Pinkerton to leave her and the fact that it is ill-advised to convert religion for a man. A devastating and tragic irony occurs when, in spite of her steadfast faithfulness, Butterfly ends up getting betrayed by Pinkerton and left behind. Her conversion and her commitment to him—which have cost her the loyalty of her family—were in vain, and she is left completely abandoned.
Sharpless and Goro discuss that Butterfly is no longer married (Dramatic Irony)
In Act 2, Sharpless and Goro discuss the fact that Butterfly and Pinkerton are no longer bound by marriage, but Butterfly does not know. Neither can bring themselves to tell her explicitly, and she resists inferring the truth, trapped in a delusion. Thus, dramatic irony occurs in which the audience again realizes that Butterfly's love affair with Pinkerton is doomed before she does.
They're taking the child (Dramatic Irony)
One of the more devastating ironies occurs when the audience learns that Pinkerton and his wife, Kate, plan to take the child that he fathered with Butterfly back to America. Not only will she be separated from the husband to whom she has devoted herself, but also from her son. Yet again, the audience learns this before Butterfly.
