Haruki hears about Kazusa's moving from her mother, who she hadn't been on good terms with.  He feels betrayed and angrily confronts her.  But his words force open the door to Kazusa's heart, which she had desperately tried to keep closed so that the three of them could stay together.
I said not to laugh!
Ich sagte, du sollst nicht lachen!
¡Que no te rías!
¡Que no te rías!
Ne te moque pas !
Já disse que não tem graça.