Those worlds with a class of people who are sluts or sex slaves. But it's not just all women or all men or what ever. Stories where the members of that class are volunteers. Where naked women on leashes walk down the street and other women fully dressed and going to work walk past. Men crawling along the pavement past a building site full of big burley men in work clothes. Yes they are different but they are not forced to be like that. They are there,like that because they want to be.