Purport Description of Sri Ujjvala-Nilamani
"There is also a book called Ujjvala-nilamani, a transcendental account of loving affairs that includes metaphor, analogy and higher bhakti sentiments. Devotional service in conjugal love is described briefly in the Bhakti-rasamrta-sindhu, but it is very elaborately discussed in the Ujjvala-nilamani. This book describes different types of lovers, their assistants, and those who are very dear to Krsna. There is also a description of Srimati Radharani and other female lovers, as well as various group leaders. Messengers and the constant associates, as well as others who are very dear to Krsna, are all described. The book also relates how love of Krsna is awakened and describes the ecstatic situation, the devotional situation, permanent ecstasy, disturbed ecstasy, steady ecstasy, different positions of different dresses, feelings of separation, prior attraction, anger in attraction, varieties of loving affairs, separation from the beloved, meeting with the beloved, and both direct and indirect enjoyment between the lover and the beloved. All this has been very elaborately described."
Caitanya-caritamrta, Madyam lila 1:41 Purport
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.