what truly touched me the most is that iz NEVER force ruby to open up.. so he looks for signs by paying attention to ruby on his own and wait for her to say something. then he always make the most out of the very few things that he knows to make ruby happy.
like he really went out of his way to make sure ruby's friends aren't killed, it surely sounded irrelevant to outsiders bc those monsters are dangerous but iz really cherishes her feelings and happiness more than anything.
it's like when you tell your loved one that you love the food they make and they end up making the same thing everyday bc they want to make you happy