To begin with, we should make it clear that Buddhist precepts are not equivalent to commandments in that precepts are training rules that are voluntarily undertaken rather than edicts or commands dictated by a higher power and/or authority. In essence, these precepts are undertaken to protect oneself, as well as others, from the results of unwholesome actions. Actions are considered unwholesome when they arise out of the mental defilements of greed, hatred and delusion.

In regard to Buddhist sexual ethics, the third precept states: “I undertake the precept to refrain from sexual misconduct.” That, of course, will naturally lead one to the question, “What is the definition of sexual misconduct?” To answer that question, however, we must take into account the other four precepts. In other words, the five precepts are an intergrated whole, and each precept supports the others. The other four precepts are (i) to refrain from harming living beings, (ii) to refrain from taking what is not given, (iii) to refrain from false speech and (iv) to refrain from taking intoxicants that lead to carelessness.

Therefore, generally speaking, sexual misconduct means any sexual conduct that involves violence, manipulation and/or deceit. As the Ven. S. Dhammika elaborates, “If we use trickery, emotional blackmail or force to compel someone to have sex with us, then this is sexual misconduct. Adultery is also a form of sexual misconduct because when we marry we promise our spouse that we will be loyal to them. When we commit adultery we break that promise and betray that trust. Sex should be an expression of love and intimicy between two people and when it is it contributes to our mental and emotional well-being.”

To summarize, from what I have been taught by my teachers, as well as from what I have read in the suttas, sexual misconduct includes any sexual activity that leads to self-affliction, to the affliction of others or to both, or that involves any person who is (i) already in a committed relationship (e.g., engaged, married, etc.), (ii) protected by law (e.g., under age, etc.), or (iii) under religious vows entailing celibacy (e.g., monks, nuns, etc.). So, in general, sex between consenting persons of legal age who are not already in committed relationships and have not taken vows of celibacy is not considered misconduct in Theravada.

One reason for this that I think should be noted is that, in Theravadin countries, marriage is seen as a secular contract as opposed to a sacred union ordained by a higher power. Marriage is certainly taken seriously, and it is still seen as a deep and powerful commitment to be sure, but it is not considered to be a prerequisite for sex. Personally, I think that a lot of the views concerning marriage and sex are influenced more by cultural, religiou, and social norms than by any universal constant. For a few quick references, please see Buddhist Sexual Ethics, Good Question, Good Answer and The Healing Power of the Precepts.

In addition, depending on the particular tradition, the types of sexual activities that are considered misconduct differ. For example, there is a prohibition against sex concerning “inappropriate orifices” (i.e. anal and oral) that can be found in Vasubandhu’s Abhidharmakosabhasyam and a few other Sarvastivadin texts, but there is no such prohibition found in any Theravadin source. Therefore, there is room for interpretation, and the precept is a basic principle rather than a legalistic rule.