She can't help it. What's inside her right now, the feeling, it's too powerful to keep secret, it's the monster in her.
It's a strong feeling and it's killing her. She knows he has a monster too and it kills him also, she just wants to let it out but he just doesn't embrace how she feels.
She cries as it kills her more. She love him and his monster, why can't he accept that?
It haunts her but it haunts him too, he feels the same but just can't let it free like her.
He's scared of his monster.