Were the three leads all related by blood? It's hard to tell since they never used anything but their first names but in the flash backs it seems that they all had the same father, unless he was a "Godfather" like the cop as well. I assumed they were all orphans or something and came together but it was never very clear and I couldn't help but thinking that the relationship was sort of incestuous. If anyone can clear this up, please do.
sharethey where talking about romance and stuff in one scene, the other guy got jealous and shot him with a pea shooter or something. so I’m guessing they aren’t related.
shareThey were all orphans adopted by Chow. They all had a brotherly/sisterly love for each other until it developed into romance in later lives.
The Goodwill Effect
It's a common theme that runs through Hong Kong/Chinese movies. Best friends tend to refer to each other as Brother/Sister, and respected elders will be called Father/Godfather/Uncle.
At least I think that's what it means.