There are charity "auctions" where women pay money for dates with certain men all the time. Why not arrange a similar party event where the guys are all black, and the women are all white, and the men bid on the women. The women could be naked and tied up, and the money could be real or it could be tokens/monopoly money/plastic coins etc. When a man has bought his "slave" he is free to use her holes as he pleases for the night/the week/be her permanent bull or whatever, be creative.