You've got to love that euphemism, "morally flexible." Next time I get caught doing something bad we'll see how well the phrase works for me. "Mike, did you take the printer in the room next to yours and replace your old one with that one?" "Yes, my work is more valuable than the teacher I took it from. You need to be morally flexible."
Creative people have been assuming for a very long time that they live under a different set of rules than those that apply to everybody else. For example, the wonderfully creative King David, writer of the Biblical book of Psalms, was taken to task by the Prophet Nathan for engaging in a questionable relationship with Batsheva (Book of Second Samuel). David, to his credit, admitted wrongdoing.
Painters, musicians, actors, and writers are probably not the best bunch for those who want a monogamous relationship.