Also known as: 不倫, 浮気, 出轨
Having sex or a romantic relationship with someone other than one's regular partner in a monogamous relationship. When this happens among married people, this is known as adultery. This can also apply to meeting another without the regular partner knowing.
For cheating in sports, a competition, or similar, see Cheating (Competitive). For cheating in school, see Cheating (Academic).