Good questions. More than ever I want to buy this one and watch again.
Let me try to explain a different way.
The only music in the movie was the scene 20 years before, where they got drunk and danced, leading to kissing and then sex, after which the two guys moved on with separate lives.
Other than that scene there was no music at all in the movie. The director left music out of the movie because he said music would shade the viewers interpretation of what was happening.
He wanted to use Love is a Stranger by the Eurythmics, during the dancing scene that led to sex, but was too expensive. That song might have been more useful than what was used, Flock of Seagulls',
, which still made a very, very good scene. I loved it. The director explained that song was also very expensive, costing as much as the rest of the movie.
(but I digress)
Now that you mention it, yours could be an awesome interpretation, that it was a bromance that happened 20 years ago. You may have hit the nail on the head.
They did meet again 20 years later (or did they?)
It may be that the director wanted to express how closeted men spend their lives fantasizing about having a great love to spend their life with. They might fantasize about another gay dude or maybe about some bromance where they got drunk and had sex one time.