*snip*. And this scene does sketch out just how lonely these two boys were, which in Ennis's case at least is odd as he is engaged to Alma. They've been waiting for each other their whole lives up to this point.
And from keren1129:
"I don't think either one of them had ever had a close friend. Someone to just talk to.
Jack felt for Ennis and his situation and probably gave him more attention than any human
being ever had."
Yep, you bet. This is my thing about always saying that, beyond and I think more important than the sexual relationship was a deep and genuine friendship of the two guys. Ennis just doesn't talk. snip ....
Jack starts getting to know Ennis there in the bar, and it continues up on the mountain. The talking is the necessary prelude to the FNIT. According to the story, after the first night of their drinking and talking, Ennis feels like he's had the best time of his life and could "paw the white out of the moon."

Edgar, your posts here are wonderful, as always, I love how you seem to come at these moments from a whole new perspective. Great observations throughout on what seemed like such a simple enough scene on the surface. Just two guys getting to know each other over a small talk and a few beers. But as you perceived, this exchange serves to both connect them and widen their views of the world. Lovely.

Had always before disassociated this first time talking at the bar with their time up on the mountain, but you make the link seem so clear now.
One of my favorite images of Jack, ever, is on that last day on Brokeback. He's finished saddling the horses and looks up at a brooding Ennis sitting alone in the meadow. There is a look of such understanding and tenderness in Jack's eyes in that moment before he walks up the hill to Ennis. A gentleness in his voice when he says "time to get going, cowboy".
I always thought Jack was reacting on his instincts, understanding deep inside the simple fact that Ennis was desperately torn up over having their time together cut short without warning. That he knew there was more emotion roiling inside of Enns then he could stand. There is that of course, but in light of what you've all just said maybe it was more?
Maybe he understood that once again Ennis was being "run off". Run off from the precious few weeks out of his lonely life where he was allowed to be truly happy. They are both being run off again, by Aguirre, and not for the last time in Jack's case.
Their whole lives - past, present and future - these two men are being run off. Run off from their dreams, their aspirations. Run off from living life as their nature begs them to live. Run off of any chance of a life together. They're run off by bad fortune and intolerance; by narrow minds and rigid social mores; and ultimately by their own choices and fears, I guess.
You're all making me think that "your folks run you off" was just the beginning .... :'(