Ethical Non-Monogamy is commonly abbreviated as "ENM".
More About Ethical Non-Monogamy
Nonethical non-monogamy is usually thought of as cheating- being deceitful by breaking rules or pushing boundaries set by those in one relationship. Even if the relationship is considered non-monogamous by both parties, it is still possible for one or more partners to cheat. While ongoing debates exist over the importance of rules in an ethical non-monogamous relationship, it is important that each party understands their partner(s)’ expectations, needs, and boundaries. Many consider other behaviors to be non-ethical such as unicorn hunting (a heterosexual couple seeking a bisexual woman to join them for sex or an ongoing closed relationship between the three of them) and hierarchy of partnerships. However these are still being debated by the polyamorous and larger non-monogamous community.