The fantasy of the well hung black lover is a common one, especially for men to have about their women. Cuckold has long been one of the more popular fantasies, and of course just because a man wants to see his lady fucked by another guy doesn’t mean the other guy has to be black, but the idea that most black men have got a bigger cock seems so ingrained in the minds of these men, it’s a natural progression for these fantasies to take.
So many of men with smaller than average cocks think of their wives or girlfriends being satisfied by another man is going to be the most arousing thing they can imagine, both for themselves watching and for their women participating. Many black men do have larger than the average white man sized penises, and that makes them excited to think of a huge, hung black guy giving it to their lady with a dick three times the size of theirs.
Many black males are also more dominant than a lot of white males as well, and many women seek a more dominant sexual partner, so they think a black lover will please their woman a lot better than they ever can, which very well may be true. One man I used to talk to had visions of his woman getting fucked by a group of large black men as he stroked his little three inch dick and he watched from a few feet away. Such a common fantasy of so many men.