When I first started it was all about cock size but after my first experience I was really turned on by his dark skin and my white hands on his body, his demeanor, his stamina, and his desire to please me. I still enjoy the cock size, and I agree 10" is not that common, but every black guy I was with was bigger then all the white guys. But more importantly is the ability to go and go until I am completely satisfied! I lost my desire for white men unless it is to put on gay sex shows which I do enjoy.
you are correct that not all black guys have 10" . For me(the husband) my IR fetish started in JR high school late 60's early 70's. there was this slutty looking girl that always hung out the black guys. One day during lunch one of the black guys was eating an ice cream sandwich and she took a bite out of it and my cock twitched. That's what I think started it. As to how I got the wife to try it in search of a cock larger than mine. I didn't know that I was blessed until we had some mfm with a few white guys and all of them were disappointments in the size department. she has had small bbc as well as large now and I will say that I can tell she gets off better with a thick 9+"