Slave -Friends
The slave girl, of course, will usually have many friends. These are, of course, almost always wenches collared like herself: Friends of her master will often bring their own girls with them, in visiting, and with these, after the men have been served, she may make friends, perhaps chatting in the kitchen. These girls may be exchanged among the men, but commonly they are not. Most masters are rather possessive about their slaves, particularly if they are fond of them. She may also, of course, meet girls in the streets, encountered in the neighborhood, or on her errands. The slave girl, almost always, has no dearth of friends. To be sure, they are likely only to be mere slaves like herself. Women desire, in their hearts, to be beautiful, helpless, conquered animals, owned and dominated by masters. The collar makes it clear to them that their dream has been enacted upon them; that, indeed, their dream, to their joy, has become their reality. They know that they are now in their place, and will be kept there. They are happy. ~ GUARDSMAN OF GOR-, Pages 209-210
Never in the books do slaves call each other sister