>>82292759
If you want a real answer from somebody who has studied sex:
There are a lot of different ideas. The primary one is it is a humilation fetish (obviously). The cucker being black matters because black men are seen as both as "thugs" (less worth) and also as "more masculine".
Them being thugs (worth less) is more humiliating because he is lesser, but still having sex with your girl. At the same time, he is more masculine, which is seen as valuable in the eyes of the fetishist.
To be blunt, the fetishest might dislike black people, BUT there is also a part of them that is scared they are inferior because of the percieved greater masculinity. This dissonance creates extra humilation.
There are also probably fetishists that have less animosyty towards blacks, but still, the perception they are masculine (and then fetishist is therefore inferior) is still a turn on. There are a lot of variations in sexuality depending on the person, but this is the general idea.
Some think humiliation is a fetish among men because it drives them to breed. See a rival fucking your girl, try to get her pregnant first kind of thing.
Happy to answer any questions.