obviously its not. PP's son looks and acts male except for genitalia. What about intersex men. Men who have XXY chromosomes. They can have physical features of both men and women.Apples & penises. As of now, we separate restrooms & locker rooms based on sex. And by that I mean the physical characteristics of male vs female. When we as a society decide that we will no longer separate in this manner, it will no longer matter. But for now, the line is clear.