basically it is the contrast. White man, white woman... The skin tones match so on video or otherwise it you have to look close. The black cock and white woman you can see the penetration real well. Not because of size but because of color contrast. So you can watch your wife from further away. that way you can see the Whole picture.
The challenge: Watch an amateur hidden video so you can see all of the couple going at it. On the white on white video it is hard to see the penetration. On the interracial video now... You can see everything. The contrasts on the colors let you see everything. And that is why people tend to go more towards interracial and not the norm... The same thing holds true if you watch black on black sex videos. You just can't see everything.
