Great post amtamburo, and I agree, its hard to keep a post short sometimes when we get to talking about our favourite boys.....
I think Jack had an inkling about Ennis from the beginning, he was the more wordly wise one of the two, and he was attracted to Ennis from day one, IMO. As far as Ennis making a move on Jack, I dont think he would have. Far too repressed and not able to articulate any of his feelings, never mind show them. But - something struck me when watching the FNIT, when they first spring apart after Ennis wakes up and discovers where Jack has his hand - when Jack goes to touch Ennis and has his hands on his face, Ennis does the same, I always find this really sweet and quite romantic, even though this isnt a particularly romantic scene (as compared to SNIT anyway) - Ennis obviously feels something for Jack, and wants to touch him in the way that Jack is touching him. I think this is the moment when Jack realises that Ennis is interested, because they stay like that for a while, and Ennis doesnt move or take Jack's hands off him. Its a very telling moment in this scene, IMO. And of course, it leads to Jack taking the lead and initiating the sex......
Oh yes, Christie -- this particular moment of this particular scene is really telling and wonderful. Just as you described -- Ennis also clutching onto Jack after Jack first grabs at Ennis's jacket. Actually (though I'm not absolutely certain of this since I haven't watched it recently (not since three days ago

how it happens at the very beginning is really great -- Ennis pushes Jack away almost simultaneously with grabbing onto him. Pushes first and
immediately grabs and holds onto him. Even when Ennis says "whudyadoin?" he hasn't moved away -- their foreheads are together. Ennis stays right where he is when Jack lets go of him and takes off his jacket...then there's the "fastest one-handed unbuckling and unzipping in the West." Anyway, another moment I love is when Ennis puts his hand...how do you say it...outstretched, open-handed...on Jack's hair, then clutches his fingers into Jack's hair. That moment, to me, is showing, okay, he has given into his wanting this too.
Of course, this is best on full-screen version, the flipping Jack over, pulling down Jack's jeans, getting himself ready...and all the rest.
Sorry this has strayed OT kind of, but I always trip out at Jack there on all fours for several seconds,
waiting, waiting for Ennis to have his way with him. For some reason, those moments really get to me.
kathy