The finer points may not be entirely clear, but the fact remains that even an action like this conveys an awful lot. Whether or not Kai can ever find it in himself to say those words, and in this moment Shinji's sure he wouldn't hold it against him if 'not' turned out to be the case, there's more than enough proof here to beat back any doubt about whether he's wanted and cared about. That's an infinitely valuable thing already. Putting words to it is second to making sure that feeling exists, and he'd hate to think that Kai was simply saying it for his benefit if it wasn't something he wanted to say.

A soft and surprised little hum escapes his throat as that hand reaches up to steady him in place, and after a moment of uncertainty, his own bit of boldness bubbles up long enough for him to tilt his head slightly, leaning in just a tiny bit more in what he hopes is an encouraging action. This? This is nice, you're doing great, Kai.