There was a point during that film where they're in the tent at night. I mean, Ennis is outside under a blanket at first, and Jack is in the tent. But it gets cold, so Jack invites Ennis in the tent. Then late at night, one takes the others hand, and then BOOM! They both quickly unzip their jeans and Ennis starts giving Jack anal sex. It was quite a shocking moment! And then the next morning, they both keep denying that they are gay and try to avoid the subject, but just end up fucking again.