Humans are narcissistic and self-absorbed. It's our nature, it's the sin in our blood. We can't help but bow to our vanity. So much can be erased by a compliment. So much can be forgiven for the right lies. Violet knows. Her love for Tate is irrational, emotional. He's a sociopath, a mass murderer, a darkness that cannot be lightened but his faults are all lessened by his way with words.
I love you, Violet.
I'll never leave you.
We'll be together forever.
She can't help but soften when he says these.