Clary Fairchild: What's with that "hey" thing?
Simon Lewis: What "hey" thing?
Clary Fairchild: The "hey" thing that guys always do. Like when you saw Jace and Alec, you said "hey," and they said "hey" back. What's wrong with "hello"?
Simon Lewis: "Hello" is girly. Real men are terse. Laconic.
Clary Fairchild: So the more manly you are, the less you say?
Simon Lewis: Right. That's why when major badasses greet each other in movies, they don't say anything, they just nod. The nod means, "I am a badass, and I recognize that you, too, are a badass," but they don't say anything because they're Wolverine and Magneto and it would mess up their vibe to explain.