He can't bring himself to stake a claim upon her; and yet he feels no indignance or discomfort at the notion of her doing so to him. Perhaps because he has, in some way, always considered himself hers-- first in terms of his duty to her, ascribed by the dictates of the Force and his own personal ethics, and later in terms of his evolved personal feelings towards her. There is no sense of role reversal-- that's just how it's always been, first in uniform and now out of it.
His lips graze her skin once more in reply, before moving upward toward the nape of her neck, and then her ear.
"Yours."
The word is singular, breathed rather than spoken, husky with its layered implication.