As a white guy, girls never let me finish inside them. So when a black guy fills a white girls pussy with cum it's an exclamation point. It makes it clear to her and the husband/boyfriend that her pussy belongs to the bull. I think that's why all three people like it so much.
Also, as a boyfriend, I love the idea of sitting next to my girlfriend while her pussy is full of another guy's cum.
Also, as a boyfriend, I love the idea of sitting next to my girlfriend while her pussy is full of another guy's cum.