One of the performers who posts around here explained in the past that the problem a lot of the girls get into is that they will have directors very early in their career who will coach them on dirty talk through a scene (*cough*Vince Vouyer*cough*, *cough*Robbie Fischer*cough). However, then the girl gets the impression that they are always supposed to do this, as it is just a part of porn performing. So, we get the fake moans and the, "Oh, you going to put that cock in my pussy?" and before you realize it the girl is narrating her own scene, describing everything that's going on.
It made a lot of sense to me.
[Link]
