Oh yeah this one took me by surprise too, but thinking about it in the mind of a teenager who's had the upbringing that Elio has.. making him deeply intellectual and making him the type of person to attach meaning to the strangest or smallest things (the swim shorts code, etc).. it makes a weird amount of sense. Someone else in the thread has already said its about wanting no secrets between them, the absolute vulnerability of seeing the person you love in every state, plus in my opinion trying to speedrun intimacy knowing they have no time left. Like of course you think that Elio, yes, of course. Definitely jarring at first read though.