Normally I wear what i want, but i'm going down to a party with a huge asian population. What could a white guy with sort of long hair wear that would be best?

Look like you can dress yourself. Try a polo and flat-front dress pants. Stand up straight. Can't outdo Asains in style.

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The biggest cock blocker, pants, that's why I don't wear any:D

Where what you usually wear, as long as it's flashy and cool.

I'm Asian and I go to parties where it's predominantly populated with white people. I do this on purpose as white girls are my preference and I think I outdress many, if not all, of the white guys at these parties. I'm an attractive asian aswell who seems to be nice on the eyes of white girls so it works really well for me.

You can use this to your advantage too. I hear many asian girls actually prefer white guys to the males of their own race so keep this in mind. You being one of the few white guys at this party will be enough alone to attract attention. Good luck!