This might be the reason why I have trouble writing them having an actual conversation in certain situations! (so maybe I'm not doing anything wrong, but they don't *need* to talk, not in words anyway).

That single scene they share together is one huge conversation within a conversation. They don't exchange many words, but facial expressions, and how much they tell wordlessly? God. GUH. FEELS. (also, amazing, amazing acting, and I can't even pick who's my favorite in that scene.)