Why does Knox give Naomi the password to his office in the novel, Things We Never Got Over?

Knox gives Naomi the password to his office after Warner violently confronts her in the Honky Tonk. Knox is furious at Warner and is very protective of Naomi. His office is considered his lair, and he lets no one in it. He lets Naomi in, however, and also gives her unlimited access because he is trying to make her feel safe.