The following is an excerpt from a discussion here on SMTR and it best describes why some people are attracted to feeling humiliated within their relationship.
WARNING: Be VERY sure you know what you are doing before employing any type of humiliation. This is one item that often backfires. BE SURE you both are fully aware of risks and dangers before proceeding. Start off slowly with gentle humiliation, then talk later about how it felt, how it continues to feel, etc. If ONE of you is uncomfortable, STOP and do not proceed further. Also do not employ innocent bystanders (Public), family or friends as your audience unless you have completely advised them up front of what will be taking place. Make sure they are emotionally comfortable before proceeding!