Hun, read your history. White men have fetichized black men lusting after their women for centuries. In a patriarchal society, women are viewed as trophies. The best trophy goes to the alpha. In a white patriarchal society white men will continually try to assert the dominance of their culture by holding their women up as the ultimate prize. It's not surprising then that many of them would get off on seeing other races lusting after their prize because it reaffirms their women, their culture, their race is the best. It's not really rocket science.
If you take another man prized possession you won. You only lose When he takes yours