Why was the lover’s love often portrayed as adulterous in courtly love literature?

In the context of courtly love literature, the lover’s affection was typically portrayed as adulterous because marriage during the Middle Ages was generally viewed as a matter of business interest or a tool for securing power alliances rather than a union based on personal affection.1

Because poets sought to idealize physical passion and devotion, they looked beyond the constraints of the marriage state. By positioning the lover as a servant to an all-powerful god of love and an adorer of his lady-saint, the literature established a framework where the lover’s service was directed toward a woman who was often already married to another man. This dynamic allowed for the exploration of love as a "delightful disease" and a demanding, faithful service that existed outside the transactional nature of contemporary marriage.1

While this portrayal of adultery was a conventionalized element of the genre, it served to heighten the intensity of the lover's experience, often involving secrecy, the outwitting of jealous husbands, and the constant threat of discovery, as seen in various medieval verse romances.23