I've mentioned this in another thread, but I'll say it here, too. Ennis and Jack are both Gay. There are many indicators in the story to support this... however, Ennis does not want to admit his homosexuality, even to himself... and Heath plays it that way, making Ennis' sexual orientation less apparent in the movie. Ennis is sexually monogamous. Jack is not. There is no "Mexico" for Ennis. He is sexually atttacted to, and passionately in love with Jack, and only Jack. When Jack goes to "Mexico," figuratively or literally, he's seeking physicality, not a love interest. His love bond with Ennis is eternal. They are "the eternal couple." Sadly, I think that the Mexico trips are also a way of "getting back" at Ennis for not setting up ranch-keeping with him, not keeping physically closer to him... something that Jack is not at all proud of. I am (or was) a kind of "Jack," and I understand those behaviors very well. Allan