Nathaniel tilts his head, offering as much of his throat as Asher wants to take.

"Because I love you... and you can break me."

No one had broken him yet, not really, but Asher... Nathaniel knows that Asher now possesses the power to crush him. He keeps waiting for his love, his trust, his obedience to be used against him, for a punishment to come for too forward of an action, of a word.