[Grantaire is, arguably, one of the more observant members of their ragtag group of dead french friends. He spots it, but he doesn't do anything. This isn't his area of expertise, comfort. He's possibly the worst at it, unable to even comfort himself, much less someone as delicate as Jehan.
No, he doesn't know what's going on, and he doesn't want to. He's concerned, sure, but he's unsure what to do.
Eventually, after a few hours of thinking on it, he sends Jehan a text.]
when you're done pouring your heart out to someone, come over. I won't go out for a walk until you show up so show up.
--> text; IN A FEW HOURS, RESPOND LATER.
No, he doesn't know what's going on, and he doesn't want to. He's concerned, sure, but he's unsure what to do.
Eventually, after a few hours of thinking on it, he sends Jehan a text.]
when you're done pouring your heart out to someone, come over. I won't go out for a walk until you show up so show up.