This isn't prostitution.  I give you sex because I dig your vibes.  You give me money because you dig my groove and our planets are in harmony.

Being an artist, I might have an easel set up with paints and a blank canvas in the room. Then say that you thought that you were here to create art. The provider is the model, because after all we are really paying for the time and or modeling priveledges.

Right?