Homosexual men are just like any other men in that although they share similiarities, in reality they each have their own individual personality. In that case, a fag hag is simply a girl best friend of any homosexual male. She may or may not have other friends who are homosexual. Just becuase she is a fag hag to one homosexual guy does not mean she will automatically be attracted to other homosexual men in terms of friendship. Some fag hag relationships will last forever, just as other friendships do, they are not merely a phase. Usually a girl will become friends with a homosexual male, not because of his sexual orientation but because she is attracted to his personality and vice versa.
The relationship between a fag and his hag can be generalised by some characteristics. They have a deep understanding and love for each other, sometimes deeper than that between sexual partners because both parties know their love ultimately stems from personality and is not tainted by sexual desire. They will always be protective of each other because although he doesn't want his fag hag (in a sexual way), he doesn't want anyone else to have her either.