In this connection, we should be careful about the so-called siddha-praṇai. The siddha-praṇai process is followed by a class of men who are not very authorized and who have manufactured their own way of devotional service. They imagine that they have become associates of the Lord simply by thinking of themselves like that. This external behavior is not at all according to the regulative principles. The so-called siddha-praṇai process is followed by the prakṛta sahajiyā, a pseudo-sect of so-called Vaiṣṇavas. In the opinion of Rūpa Gosvāmī, such activities are simply disturbances to the standard way of devotional service.
Śrī Rūpa Gosvāmī says that learned ācāryas recommended that we follow the regulative principles even after the development of spontaneous love for Kṛṣṇa. According to the regulative principles, there are nine departmental activities, as described above, and one should specifically engage himself in the type of devotional service for which he has a natural aptitude. For example, one person may have a particular interest in hearing, another may have a particular interest in chanting, and another may have a particular interest in serving in the temple. So these, or any of the other six different types of devotional service (remembering, serving, praying, engaging in some particular service, being in a friendly relationship or offering everything in one's possession) should be executed in full earnestness. In this way everyone should act according to his particular taste.
Devotional service following in the footsteps of the gopīs of Vṛndāvana or the queens at Dvārakā is called devotional service in conjugal love. This devotional service in conjugal love can be divided into two categories. One is indirect conjugal love, the other direct. In both of these categories one has to follow the particular gopī who is engaged in such service in Goloka Vṛndāvana. To be directly attached to the Supreme Personality of Godhead in conjugal love is technically called keli. This keli performance means to directly join with the Supreme Personality of Godhead. There are other devotees who do not wish direct contact with the Supreme Person, but who relish the conjugal love affairs of the Lord with the gopīs. Such devotees enjoy simply by hearing of the activities of the Lord with the gopīs.
This development of conjugal love can only be possible only with those who are already engaged in following the regulative principles of devotional service, specifically in the worship of Rādhā and Kṛṣṇa in the temple. Such devotees gradually develop a spontaneous love for the Deity, and by hearing of the Lord's exchange of loving affairs with the gopīs, they gradually become attracted to these pastimes. After this spontaneous attraction becomes highly developed, the devotee is placed in either of the above-mentioned categories.