She thinks he is cheating. In reality he is not, he is in love with his partner. She suffers from sleepwalking... he tries to create a comfortable atmosphere, tries to protect her and prevent harm. She does not remember anything from the night. During the day they are like two strangers, they argue and avoid each other. In the last scene, she reacts annoyed at the touch of his hand... but he remains there still, unmoved, saying nothing and accepting.