Ive just watched the movie again for the "lost count" time, and as I always do, I replay that reunion kiss over and over and over again.....never get tired of watching it.......
It finally hit me today, what I think happened......the initial strong hug between the two, and during that hug, Ennis realized probably for the first time, that HE WAS GAY, and that he loved Jack, more than he had ever loved anyone else before, and it was that emotion that then made him kiss Jack so hard, like he couldnt get enough of him........then the look Jack gave Ennis, of realization too, like, "this bloke loves the hell out of me, I'll show him too, just how much I love him"...and turned him around and pressed his face and lips into Ennis's........
And later as Ennis, laid in Jacks arms at the motel, so comfortable, like it was where he belonged......
Yes, Ennis had no doubts, he was in the arms of the love of his life.......