[He opens his eyes again and looks down at her, smile still on his face.]

I feel as though you've stolen the words right out of my mouth... but a demon like myself doesn't deserve to be the target of a love so selfless. You should desire more-- and if I could give you more, it would surely make me the happiest person in all of Nysa.

[His smile doesn't wane, but there's something akin to sadness in his voice as he continues.]

But... I cannot. I can neither grow old with you, nor give you a family. Nor can I promise you fidelity, seeing as I would never make a promise I know I could never keep. And for all that you know plenty about the sort of person that I am by now-- there's still so much about me you don't know.

But even knowing-- even knowing all of that, I...

[He's not actually trying to convince her of anything. Perhaps the one he's really trying to convince is himself.]