Many women do more than that when they're alone with themselves. But the contrived rules do not allow them to relax with a partner. It is not without reason they say, that a smart woman has it in her head, a fool has it in her mouth. I even know men who categorically reject such liberties.
The nigger was clearly a good mentor, and does not let the girl relax. The blow job was excellent, and the guy would remember it for a long time, because he was thrilled.