sardothiened:

The Infernal Devices by Cassandra Clare

“They say you cannot love two people equally at once,” she said. “And perhaps for others that is so. But you and Will—you are not like two ordinary people, two people who might have been jealous of each other, or who would have imagined my love for one of them diminished by my love of the other. You merged your souls when you were both children. I could not have loved Will so much if I had not loved you as well. And I could not love you as I do if I had not loved Will as I did.”