For me the scene where Ennis goes to Jack’s parents… that face, that cold man of a father in front of suffering Ennis, showing nothing but hatred, and the frighten mother, who was looking at him seeking permission all the time.
The moment Ennis came back downstairs with the two shirts in his hands.
(I held the armrest of my chair until I had white knuckles, I feared the old man will not consent Ennis to take those with him).
If you look the way Ennis is holding the shirts on the other side of his body, as to shield them away from the old man’s eyes, Ennis was holding dear Jack in his hands… at that point I could see Ennis’s hands on the old man’s throat fighting to take that piece of Jack with him, if he did tried anything.
The looks on both their faces, old man’s said “what you have there boy?” and Ennis’s “just try to stop me old man”.
Old man then said, to dig deeper into Ennis’s broken heart, “tell you what, we’ve got a family plot, he is going in it”… only Ennis won this time, because he was leaving with Jack’s declaration of eternal love for him and that was more important than Jack’s remains. Ennis had something real to touch and to hold until the end of days.
In my heart I believe “Jack, I swear” means that when Ennis would die, he and those shirts would be cremated and the ashes scattered on BBM as Jack’s final wish, finally together.