Cross-cultural dialogue

Taking my regular morning trip to Espresso Metro, I ran into Alex, the personal trainer from my gym, talking to a married couple who were there with their kids. Alex commented that I don't look my age, and I said, "When you're Asian, you subtract ten years. Except I'm half-Asian, so you should subtract five years." The wife of the couple, who were both white, said, "They say that 'black don't crack.'" "What does that mean?" I said. Alex, who is black, said, "It means that black people don't wrinkle." He indicated the white couple and said, "Yeah, you do get wrinkled. But you sure can make money!"