L Racisto o L Homosexualo?

I'm standing over a twentysomething black guy on the L in Brooklyn, and I want to indicate to him that his fly is unzipped, but I'm seriously afraid that this has become, unbeknownst to me and other colorlesses, a new urban fad and that my indication of such trousal openness will be viewed as archaic and racist. So now I have to stare at every black male crotch I see. You know, for research.
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