sentences:  Some Masters adopt a holistic approach to the maintenance and long-term development of their slave by using such models as Maslow's hierarchy of needs.Sexual slavery is a consensual exchange of power by the submissive to the dominant, though the scope of the surrender of discretion may be limited and may be withdrawn at any time.The types of activities that the sex slave may be expected to perform are usually defined in advance and sometimes spelled out in a slave contract, a document without real value that outlines the desires, limits, and expectations of the parties.