Pastor Fred:
One of the most beautiful aspects of the love between Ennis and Ellery is the way they draw strength from each other. Each man is more fully himself because of the relationship they share. As Ennis comes out of his emotional repression, he is able to provide Ellery the safe haven for healing and growth that Ellery has given him. That is a paradigm for a love relationship to benefit all of us.
Like your point, Now the next step. Ellery is providing Ennis Love, room to grow, a safe environment.
What is Ennis providing Ellery?
Well, from my viewpoint, Ennis is someone who is manly and strong who isn't violent or controlling of Ellery in a sexual way. The need to submit is intimately related to Ellery's need for nurturing, and this is manifested in how Ennis cleans up, makes food, and does other caretaking chores without ever being asked. Ennis is doing his part to care for both of them, so both of those elements are there. All of that hot fast hard sex, too, don't forget (like anyone is going to forget, here,) and a willingness to indulge Ellery's undoubtedly kinky side, which has introduced Ennis to a side of sex he only glimpsed when he got inspired one day to tie Jack down. Ellery didn't ask for Ennis to tie him up until he learned of this event, and it opened up a world for both of them, and a little mention of spanking one day opened that avenue as well.
One thing that has really only begun to unfold is Ellery's realization that Ennis is someone he can lean on when HE falls apart, too. It isn't all about being queer and accepting it, there is a world of scary emotions and the scars of the past, and while he has had Wes and Edna to lean on, he has always been reluctant to take their support. He accepts help far more readily from Ennis, and in a form that he accepts it. (A spontaneous bedroom encounter - or two - after an emotional rollercoaster can do wonders for the self esteem.)