I've always been a little puzzled by why Alma waited so long before confronting Ennis about his relationship with Jack. After all, there's almost ten years between the reunion kiss and Alma's outburst in the kitchen after Thanksgiving dinner:
1963. Ennis marries Alma.
1967. Sept. 24. Reunion kiss.
1972. July/August. Ennis almost forgets creel case.
1975. Nov 6. Divorce.
1977. Nov. Thanksgiving dinner.
We know that Alma, after seeing the reunion kiss, hatches a scheme to find out more about these "fishing trips" that Ennis and Jake take together. This is how Alma explains it in the kitchen scene:
"So one time I got your creel case open the night before you went on one a your little trips - price tag still on it after five years - and I tied a note on the end of the line. It said, hello Ennis, bring some fish home, love, Alma. And you came back and said you'd caught a bunch a browns and ate them up. Remember? I looked in the case when I got a chance and there was my note still tied there and that line hadn't touched water in its life."
It is not clear when this happened. However, there is one scene in the movie in the July/August of 1972 when Ennis almost leaves without his creel case and Alma calls his attention to this. Of course, his forgetfulness could simply suggest that fishing wasn't the first thing on his mind as he hurries off to meet Jack. Alma, however, would have even more reason for not letting Ennis forget his creel case if that's the occasion when she has concealed the note within it. If that's the case, Alma would have had her suspicions about her husband and Jack more or less confirmed by the late summer of '72, yet still she chooses to remain silent.
They divorce about three years after this (Nov.6, '75) and Alma, with a fair degree of rapidity, marries Monroe. By the Thanksgiving scene, she is comfortably settled in her new house and, in addition, is about four or five months pregnant. So, all in all, it seems as though Alma is now enjoying the domestic security and financial stability that she scarcely ever enjoyed with Ennis.
Yet, it is at this point in her life, that she at last brings up Jack and throws their affair into her ex-husband's face. Why? And why then?
I have a few half-formed explanatory notions of my own but would be delighted to hear from others what they think on this topic.