Little observation time

I was just thinking about something. You notice, after the divorce, I mean, Ennis does not go looking for women. As if to say he's perfectly content being alone, except for Jack. Almost as if he really could be content with just his get togethers with Jack.
But, Jack on the other hand, is having an affair with LaShawn, he's seeks out other women.
Yes, Ennis hooks up with Cassie and "puts the blocks to" her as he puts it. But he doesn't seek it out.
Is this because he really only wants Jack, and even though in his world it will never be him and Jack exclusively?
I just started to wonder about this a few minutes ago, anyone else have anything on this?
Ann