He tries to get her to say "you luv black cock" but she doesn't comply... so he thrusts even harder which leads to her having orgasmic spasms in a retard-like manner.
If your penis is insufficient, watch this video and learn how to give a girl an orgasm so big that she'll giiggle like school girl and love you forever. This would be quite a change for me, most girls just spit in my face after sex. They just can't seem to appreciate ass 2 mouth.
The medical bills for stitching up a busted asshole probally outweigh whatever she was paid to be in this porn. She doesn't even notice the prolapse happen lol.
I like to believe this has less to do with his cock and more to do with her vagina. Some girls are just extremely sensitive down there, and I think that even a 3 inch pecker such as my own could produce the same results. Don't pity me for having hope.