[Rex doesn't know how to respond to that, even with the addition of the half-hearted joke. He's usually so callous, so used to heightened situations of such preposterous levels of intensity, that something like watching a person cough would elicit zero concern from him.

And yet here he is, observing Denji carefully, with no well-thought out words to describe how uncomfortable it is to watch the other boy cough up smoke. An especially hilarious thought, seeing is Rex well-aware that Denji can survive having entrails literally hanging out of his slender body. In some ways, that's why the display is a little off-putting, because Denji is taking yet another difficult stride to make himself feel better, or feel...

Something.]

Is... Whoever it is okay?

[Rex understands that he can't say what he's thinking, especially since it's so bizarre.

"I'm worried about you."

But are they even-]

Your friend?

The one you were trying to protect? I remember you sayin' something about that.