Proper and improper relationships for practicing Kama

For the practices of Sexual Kama, there are relationships which are permitted, others which are prohibited, others which are not prohibited, and others which are required as a matter of duty. The sexual act is understood to commence with flirtation and courtship.

In every case, the sexual act must be undertaken by mutual consent, motivated by love and never for carnal desire. Those undertaking sexual acts must be truthful to each other in all things, and trust each other, and devoted to the relationship they enjoy. They should not be shy with each other, and be courteous to each other. They should know the appropriate times and places for displaying their affections.

Sexual relationships which are prohibited:
With anyone who is immature
By anyone joined in monogamous marriage with one to whom they are not married
In polygamous relationships in any way that would violate marital devotions and duties
With anyone who has sworn an oath of chastity or abstinence from sex
With the insane
With those unable to consent
With those who are highly emotional or distressed by mental illness or otherwise acting irrationally
With a person who has not gotten "over" their last relationship
With a person who is not a friend, or cannot be trusted like a friend
With a childhood friend
With a servant
With one whose interests are identical to your own
With one with whom you frequently do business
With those who do not practice adequate hygiene
With a fellow student, a colleague or coworker
With a relative
With a person who is under your protection, instruction, guidance or command
When the relationship must be kept secret from family and friends
When the relationship would result in the communication of STD's or other disease
When the relationship is illegal

Sexual relationships which are required by duty:
Between those joined in marriage: spouses enjoy the duty of sexual relations
Between those whose civil duty is to enjoy sexual relations (such as in monarchical societies in which inter-state treaties were sealed by sexual relationships between houses)

Sexual relationships which are permitted or not prohibited
Relations between consenting, mature adults who are not married, including those who have not yet married, divorcees and widow/ers.
Relations between consenting, mature adults for the purpose of gain or exchange (as in consortium or prostitution). Prostitutes and Consorts may undertake sexual relations for the purposes of obtaining influence or power, for obtaining wealth, for self-protection or the protection of others, for social access, for economic access, for political access, for the purpose of ending conflict, etc.
Human sexual form and behavior is divided among male, female and transsexual forms exhibiting heterosexual, homosexual, bisexual and aesexual behaviors; the Dharma does not proscribe nor prescribe among the four behaviors.  Nor is any general proscription or prescription indicated for monogamy or polygamy: these practices, along with abstinence and chastity, are seen as spiritual practices distinct from sexual relations.