Sharpless asks Butterfly if Pinkerton knows about the child, and she tells him that he does not. She then tells Sharpless to write to Pinkerton and inform him that his son is waiting for him, in order to encourage the lieutenant to come back sooner. Butterfly talks to her son, telling him that Sharpless was just suggesting that she should go and beg for money, returning to her life as a geisha. She addresses Sharpless, telling him that she would rather die than be so humiliated.
Sharpless tells Butterfly that he must go, and asks her son what his name is. Butterfly speaks for the child, telling Sharpless that his name is "Sorrow," but it will be "Joy" when Pinkerton returns to them. Before he goes, Sharpless tells Butterfly that he will tell Pinkerton about the child. They are interrupted by Suzuki yelling and dragging Goro onstage. She says that Goro has been spreading rumors that no one knows who Butterfly's child's father is, and ruining her reputation. Goro tries to tell them that a child born under a curse in America is always rejected.
Butterfly is enraged and grabs a dagger from a nearby shrine, threatening to stab Goro. When Goro runs away, Suzuki brings the child into another room and Butterfly tells him that one day, his father will return and bring them both to America.
Outside, a cannon goes off and Suzuki and Butterfly run to see a ship arriving in the harbor. The ship is called the Abraham Lincoln, and the two women sing "Il cannone del porto!" (also known as the Flower Duet). Butterfly believes that this ship is carrying Pinkerton back to her. Believing that she has around two hours until Pinkerton arrives, she orders Suzuki to draw her a bath for her and fill the house with flowers in anticipation of Pinkerton's arrival.
Suzuki asks Butterfly which flowers she ought to gather, and Butterfly instructs her to gather all the flowers from every bush and plant on the property. When they have gathered the flowers, Butterfly sits down at her dressing table and tells Suzuki to adorn her, and also bring her child to her. Butterfly puts rouge on both her and her son's cheeks, and thinks about how she will be made so happy after being so disgraced by her family. She then puts on the dress that she wore when she was married and tells Suzuki that she wants to wear a red poppy in her hair.
As night falls, they wait for Pinkerton, but he does not arrive. Suzuki and Butterfly's son go to sleep, but Butterfly remains awake. She can hear sailors singing as the sun rises in her home.
Complicating matters even further is the fact that Butterfly has given birth to Pinkerton's child. This consequence of their short marriage is a constant reminder to her of their love affair, as well as a way for Butterfly to feel all the more connected to her American husband, even though they have not seen each other for a long time. The child makes Pinkerton's crime that much more visible to the world, as he not only led on Butterfly, but left her with a child to take care of in his absence. The fact of their child raises the stakes of the opera and the potential damage that Pinkerton could do to the vulnerable and helpless Butterfly.
Butterfly's delusions continue when she sees the Abraham Lincoln dropping anchor in the harbor. Instead of listening to reason and deducing what Sharpless was trying to communicate to her, she becomes sure that the ship must be carrying Pinkerton, and rejoices at his arrival. In her mind, he will be happy to return to her and pursue a relationship further, even though we know that this is hardly the case. The tensions rise as the audience realizes just how heartbroken Butterfly will be when she learns the truth, heightening the tragic dimensions of the narrative even before the devastating rejection takes place explicitly.
As she prepares for Pinkerton's arrival, Butterfly gets swept up in a grandiose reverie, instructing Suzuki to gather every flower from every plant she can find, filling the house with flowers. Her delusions lead her to maximal fantasies, notions that push the limits of reality, all for the sake of beauty and romance. Pinkerton's return becomes the cause for an extreme performance, something to impress and intoxicate. Thus, we witness the ways that Butterfly's desperation pushes her past the bounds of propriety and into a more impractical, dramatic realm of being. This realm of being, in all its tragedy and excess, is well-suited to the operatic stage, a realm built for excess and heightened spectacle.
While the emotional and musical landscape of the opera is quite diverse, reaching many peaks and valleys, the narrative in this part of the opera is rather monotonous, closely following Butterfly's conviction that Pinkerton will return. In spite of every indication to the contrary, she is loyal to her husband's memory, certain that it is only a matter of time before he comes back and they live happily ever after. If Butterfly can be thought of as a tragic heroine, her tragic flaw has to do with her impenetrable convictions, her faith in the face of undeniable discouragement.
The tragedy of Butterfly's plight also has to do with her conviction that she can recreate the past. She is trapped in the memory of her early moments with Pinkerton and his acceptance of her after the trauma of getting disowned by her family. It is as though she is arrested in the moment of their initial union, trapped in a moment that has long since past. This is especially evident in her desire to recreate her wedding appearance for Pinkerton's return.