Boromir attending Aragorn’s coronation and feeling such an overwhelming sense of pride like “my boy is all grown up”
Boromir and Aragorn crashing together in a hug so meaningful and pure and Aragorn saying with great feeling, “The Lords of Gondor have returned” making the Captain of the White Tower unable to reply for the wave of emotion.
Boromir and Aragorn going on hunting trips with Legolas and Gimli and all of them ganging up on Faramir teasing him about Eówyn.
Boromir having a son and telling him the story of how he met Uncle Aragorn and their rampaging adventures through Middle Earth.
Boromir living to see the glory of Gondor restored.