Originally Posted by mikesouth

It's not a loophole and the legal argument is very simple.

When you shoot a girl there are 2 copyrights to the work, yours and hers neither of you can do anything with that content without the others consent, this consent comes in the form of a model release that releases the models copyright to the photographer, or a photographers release that releases the photographers copyright to the model.

What you are paying for is the release of the copyright, not the sex.