I...

[It's finally registering, the full extent of what could have happened. Or why Rei's upset. Toki doesn't ascribe much worth to himself, but Rei means everything to him. Only now does he really understand that it's the same for her. Toki had been willing to die with Rei in her dungeon, because he couldn't imagine a life without her. What if he had died here, and forced her to go on without him?]

I'm so sorry.

[Now he's crying too, as it all hits. How horribly this could have turned out, and why? Because he made another stupid, impulsive decision without thinking of any consequences.]

I should have just walked away. It wasn't worth it, and I hurt you because you had to watch, and worry...

[He tries to push her away a little, so he can look into her eyes.]

Rei, I promise... I promise I won't do anything like that again. It wasn't- it wasn't trying to protect you from them, it was... acting on jealousy that... it's so stupid, because you would never have even talked to them after they said those things, but I...

[Toki looks away, because these words can't be said with eye contact. There's too much shame and self-disgust in them.]

I know it's not true, I do, but somewhere inside I'm just... afraid. I'm afraid you won't always be mine.

[He doesn't mean it in a possessive way; more doubting that something this good can last, and hasn't fallen apart- when will it?]