Another reason for why one cat hooks up a chick that's been around the same circles is that she's become part of the club, and basically knows her place within. She's gotten the stamp of approval - she's vouched for. They don't complain or demand too much. She's never tried to sue another baller. So they go with that rather than hunt for something new. Even in less famous circles, there's sometimes that girl that gets passed around within. Guys get past the incestuous nature of it because it's easy.
"The best kind of pride is that which compels a man to do his best when no one is watching."