So in the next episode [EP. 6] we’ll see Kinn resting/sleeping next to Porsche and it’s most probably his first time ever doing so with an actual ‘stranger’.
He already realised Porsche isn’t just anyone to him, that’s why he’s okay with it, that’s why he looks so carefree and peaceful.
I still don’t think we’ll see Kinn actually falling asleep though, not because he doesn’t trust Porsche completely yet but simply due to the nature of his character, he is paranoid and doesn’t trust the given situation they’re in.
There’s still progress though! Remember how in episode 3 before their first kiss at the pier, Porsche lay down and wanted Kinn to do so as well? Sure, he did and, on top of that, enjoyed it but it only took him a few seconds to 'come back to reality’ and get up again.
This time however, on that truck, he doesn’t get up at all. He might not fall asleep 'peacefully’ like Porsche does but he feels at ease next to him.
