Śrīmatī Rādhārāṇī is fifteen days younger than Kṛṣṇa. She always keeps Her hand on the shoulder of one of Her friends, and She always talks and thinks of pastimes with Kṛṣṇa. She always offers Kṛṣṇa a kind of intoxicant by Her sweet talks, and She is always prepared to fulfill all His desires. In other words, She supplies everything needed to meet all the demands of Śrī Kṛṣṇa, and She possesses unique and uncommon qualities for Kṛṣṇa's satisfaction.
In the Govinda-līlāmṛta a nice verse states: “Who is the breeding ground of affection for Kṛṣṇa? The answer is that it is only Śrīmatī Rādhikā. Who is Kṛṣṇa's dearmost lovable object? The answer is that it is only Śrīmatī Rādhikā and no one else. Sheen in the hair, moisture in the eyes, firmness in the breasts—all these qualities are present in Śrīmatī Rādhikā. Therefore only Śrīmatī Rādhikā is able to fulfill all the desires of Kṛṣṇa. No one else can do so.”
Satyabhāmā is a competitor of Śrīmatī Rādhārāṇī’s, but she always desires to come to the standard of Śrīmatī Rādhārāṇī. Rādhārāṇī is so expert in all affairs that all the damsels of Vraja come to learn arts from Her. She is so extraordinarily beautiful that even the goddess of fortune and Pārvatī, the wife of Lord Śiva, desire elevation to Her standard of beauty. Arundhatī, who is known as the most chaste lady in the universe, desires to learn the standard of chastity from Śrīmatī Rādhārāṇī. Since even Lord Kṛṣṇa cannot estimate Rādhārāṇī’s highly transcendental qualities, it is not possible for an ordinary man to estimate them.
After hearing Rāmānanda Rāya speak of the qualities of Śrīmatī Rādhārāṇī and Kṛṣṇa, Lord Caitanya desired to hear from him about the reciprocal exchange of love between Them. Rāmānanda Rāya described Kṛṣṇa as dhīra-lalita, a word indicating a person who is very cunning and youthful, who is always expert in joking, who is without anxiety, and who is always subservient to his girlfriend. Kṛṣṇa is always engaged in loving affairs with Rādhārāṇī, and He takes to the bushes of Vṛndāvana to enjoy His lusty activities with Her. Thus He successfully carries out His lusty instincts. In the Bhakti-rasāmṛta-sindhu it is stated: “By His impudent and daring talks about sex indulgence, Kṛṣṇa obliged Śrīmatī Rādhārāṇī to close Her eyes, and taking advantage of this, Kṛṣṇa painted many pictures on Her breasts. These pictures served as subject matter for Rādhārāṇī’s friends to joke about. Kṛṣṇa was always engaged in such lusty activities, and thus He made His youthful life successful.”