But he did seem careful around other people. He was afraid of Alma telling Monroe, even though I think she already had done that. And Cassie was completely clueless about Ennis, so he seemed to be doing a good job of keeping his secret from everyone in Riverton except for Alma. Maybe he resented Alma because he felt so trapped in his marriage with her, doing what society expected of him, no matter how unhappy and miserable it made him, that he didn't care if Alma knew. Part of why he was so careless around Alma was simply because he was just so excited and happy to see Jack that he forgot everything else, all his troubles and worries flew out the window as soon as he knew he would be back in Jack's arms. But I think also part of it was that his resenting Alma, just like Jack resented Lureen, the resenting of that lie they were forced to live, the chains that society had placed them in. Ennis was definitely afraid of anyone finding out, including Alma, but his resentment gave him a sort of careless abandon regarding what she thought. He no longer cared what she thought, I think it was that fighter coming out in Ennis. Ennis was always the one who was afraid, the one who thought he was powerless and had no choice but to comply with society's rules and the cruel circumstances of it, but there is no doubt that his deep and immense love for Jack, finding that true love brought out the maverick in Ennis. While he was still in chains for the most part, Jack had lit that spark in him to fight for love, even though it was just a tiny spark. In the end, he realizes he should have done much more, he should have listened to his heart and not cared about anything else, he should have been true to himself and never let society's iron chains make him miserable, but while Jack was alive, a tiny bit of that spark was there, and it manifested itself in how he dealt with Alma.