[He kind of- he doesn't wibble, exactly, but can tell where Shiro's emotions are getting all over the place and can't help respond to it, even without fully understanding it, holding onto his hand even if he was thinking about letting go.]
Shiro-- I. [He can't begin to put into words everything he could ever want to tell him, but.] Thank you.
No one's ever believed I'd do things like this before you. I didn't even think... [Here you are STILL believing in him. Truly never giving up on him. He can't handle it.]