Thank you for this good thread, friends.
I tend to feel angry/irked with Ennis when he withholds from Jack his expression of love. So when Jack says, "Truth is sometimes I miss you so much I can hardly stand it," and Ennis says nothing at all back, I start getting pissed off at Ennis. And then when I see him holding Jack while Jack is asleep, I think "Why can't you show him that tenderness when he's awake?" And I hope that Jack can be aware of the holding, but worry that he's sleeping through it and missing it.
My annoyance with Ennis around his not responding to Jack's "Truth is..." speech was mitigated when I realized (through someone here pointing it out) that when Jack says those powerful words of yearning and pain, Ennis must feel piles and piles of guilt and dread, because he already knows that they won't be seeing each other til November, but still hasn't told Jack yet. So, as always, my annoyance with Ennis melts into "Poor Ennis," for his plight.
As to Jack's arm, it looks like maybe it could be as you propose, Sheyne. And who knows, we just see that they are wearing shirts. Who knows what their pants are doing. Maybe they fell asleep with Jack pulling Ennis close in.
P.S. That's my favorite shirt of Ennis's. He wears it in the truck scene with Alma Jr. too. It looks like it has feathers on it. Ooo! Must go to bird thread and post that observation.