Some people fall in love over and over again, not always as deeply but no less genuinely. Other people fall in love once and that's it; Ennis always strikes me as one of those. Jack's the first person who's ever taken any real notice of him, shown he thinks him interesting, made him laugh, talked to him then made it clear he wants him physically. I wonder how far the same is true of Jack; his previous experiences, whatever they were, needn't have been prolonged or much more than passing physical things while Ennis pays him the great compliment of talking more to him than he has to anyone else for the last year ( and that must include Alma). Then they do things together, create a sort of domestic scene, the kind they m,ay not have often seen with their families - but above all they spend time together. Jack seems to me to be such a mobile charatcer, volatile almost, that Ennis may seem like an anchor, something to cling to.