Vronsky is angry because Anna seems to be deliberately misunderstanding her position. For Anna to appear at the opera is to deliver a slap in the face to society. He's confused as to why she wants to do this.
Vronsky hangs out with Yashvin for a bit, and then a servant comes in to tell them that Anna has left for the opera.
Yashvin gets up to join Anna, but Vronsky refuses.
Vronsky starts pacing around the room, imagining Anna at the opera. Finally he comes to the conclusion that he must make an appearance.
Anna looks beautiful at the opera house.
Vronsky sees that, in the box next to Anna's, is a couple by the name of Kartasov. Anna is acquainted with them, but the woman is obviously saying angry and spiteful things about her. The wife can't believe that she has to be seen near that woman. Kartasov tries to calm his wife. After his wife leaves, he tries to bow to Anna apologetically, but she ignores him.
Vronsky doesn't know exactly what happened between the Kartasovs and Anna, but he realizes that it was a humiliating experience for her. He goes and searches for some information.
He runs into his sister-in-law, Varya, who says that Madame Kartasov insulted Anna deliberately.
Vronsky then runs into his mother, who says that everyone in the opera house is disregarding the singer in favor of gawking at Anna.
When Vronsky goes home, Anna is already back. As soon as Vronsky comes into the room, she begins blaming him for everything.
Apparently, Madame Kartasov, said it was a disgrace for her to sit next to Anna.
Anna argues that if Vronsky loves her, he wouldn't have driven her to go to the opera.
He soothes her and assures her of his love with words he thinks seem really clichéd, but that Anna drinks up.