This is a very interesting conversation . '
I'll add my two cents by saying that Ennis was'nt even thinking of Mexico, until Jack himself mentioned Mexico, like atalley says. (" We otta go to Mexico" )I think it gave Ennis a clue. He puts two and two together and concludes that Jack has been there. If it was sex with a woman Jack needed, there was Lureen, and possibly a foremans wife.. Why would Jack go to Mexico? alone. In Ennis mind, it's where "boys like you" go to play. Possibly on more than one occassion? Men, and sex with other men. When Jack speaks of "needin somethin he hardly ever gets", it's sex with another man.
I don't even feel that what Ennis felt he had on Jack was considered a *leash* to him. Those were Jack's words, how he felt. Ennis simply expected Jack to be faithful to him, because to Ennis, they had an unspoken * arrangment that they would be the only men either would be sexually active with and Jack was breaking the *unspoken* rule. Sure he was jeaulous, he loved Jack, Jack was his partner/lover in a supposedly monogamus relationship. Unfortunately, Jack had a much higher sex drive than Ennis. Once or twice a year is just not enough. MO