I personally don't care if people want to mix outside of their race, so to speak. Because I'm a libertarian, even if I see something that I don't really agree with (like someone hiring a prostitute in Nevada where it is legal, for example), I would still be glad to see it in a weird kind of way if free will is being practiced and the government isn't sticking their nose in (miscegenation used to be illegal, of course).
That being said, family is different. My sister (who lives in Vegas) is dating a Mexican, and I no longer speak to her because of it. It is something that, although my parents more or less accept it, I know they don't agree with it. My other sister (who lives here in Alabama) knows better than to do such a thing, because she respects the wishes of her family. If the Vegas sister doesn't want to do that, she can deal with no longer having a brother. When her relationship with the guy ends, our familial relationship will not resume (atleast not for quite some time), and she can learn a harsh lesson from that. There is too much of a stigma attached to mixed-race couples, so it is best to avoid them.