My take on it was that they started out happy but she let her insecurities take over. She became jealous and possessive which in turn drove him away from her emotionally, although it seems like a physical split is shortly to follow.
She realizes she's a monster for what she's done, and while it pains her, she thinks the only way to keep him is to kill him. Basically a, if I can't have you no one will, kind of thing.
My take on it was that they started out happy but she let her insecurities take over. She became jealous and possessive which in turn drove him away from her emotionally, although it seems like a physical split is shortly to follow.
She realizes she's a monster for what she's done, and while it pains her, she thinks the only way to keep him is to kill him. Basically a, if I can't have you no one will, kind of thing.