That hand reaching over and touching his manages to pull him back out of his thoughts and into the present moment, and it doesn't take much more than a tiny bit of that guidance before Shinji convinces himself to, at the very least, turn a wide-eyed look toward Kai.

"I'm sorry," he offers quickly, his hand only moving away enough to make sure the apology is heard nice and clear despite how tight his throat suddenly feels. "I didn't... mean to say that out loud."

Another very honest statement which, for what it's worth, is a confirmation that it should have stayed right in his head, but isn't a thought that would have been out of place just staying quietly within those confines.