Something Im Seeing In Pornos......

Im noticing quite a bit that the female in hetro pornos id spitting on her hand then rubbing that on the member before insertion or re-insertion.
Is the problem that he has a dry dick?
Do many girls do this in.real life or do they go to the root of the problem directly?

Im going to go for a double header here with another porno related question.
Why do these beautiful actresses not bother to fake an orgasm? I mean in proper porn not the soft kind where the whole thing is an act or maybe that isnt even made anymore.