A blackaholic is a white woman who only dates black men, and who always refuses to go out with white guys. She prefers black men because they are taller, more musical, more charming and also because they have bigger penises.
Blackaholics are not necessarily sluts, although sometimes they are mistakenly believed to be sluts.
Rosa is a blackaholic. Being herself white, she refused to go out with Michael because he is white. She told Michael that she only dates black men.