Just like the sun and the sunshine are non-different from each other similarly Lord Krishna and Srimati Radharani are inseparable from each other. Just as sun is the source of the sunshine similarly Lord Krishna, the Supreme Lord, is the source of everything in the entire creation.
He is even the source of Radharani. Krishna is complete in himself and when he wants to enjoy loving exchanges then he expands himself as Srimati Radharani. So Srimati Radharani is the internal potency of Krishna.
Krishna is supremely energetic and Radharani is the supreme energy of Krishna. Krishna is the masculine aspect of absolute truth and Srimati Radharani is the feminine aspect of the absolute truth.
Srimati Radharani and Lord Krishna are one and the same but they have eternally separated themselves to enjoy transcendental loving exchanges with each other. “Her mind, senses and body are steeped in love for Kṛṣṇa. She is Kṛṣṇa’s own energy, and She helps Him in His pastimes.” Chaitanya Charitamrita Adi lila 4.71. Just like sun without sunshine is incomplete similarly Lord Sri Krishna without Srimati Radharani is incomplete.
Srimati Radharani to give maximum pleasure to Krishna and to make the lilas (pastimes) more colorful expands herself as different consorts of Krishna. Chaitanya Charitamrita Adi lila 4.80 explains, “Without many consorts, there is not such exultation in rasa. Therefore there are many manifestations of Srimati Radharani to assist in the Lord’s pastimes.”
The millions of goddess of fortune in the Vaikuntha planets, the queens of Dwarka and the gopis who are eternally serving Krishna in Vrindavan are all expansions of Srimati Radharani. “The beloved consorts of Lord Kṛṣṇa are of three kinds: the goddesses of fortune, the queens, and the milkmaids of Vraja, who are the foremost of all. These consorts all proceed from Radhika.” CC Adi 4.74-75.
So when Krishna is relishing loving exchanges with the gopis then he is actually enjoying with his own internal potency.
Krishna having different pastimes with the gopis is like a child playing with his own shadow.
Most of us misunderstand the relationship between Krishna and Radharani because we consider them as ordinary boy and girl. But if we delve deep into the scriptures and try to understand the teachings of great realized souls then we would start understanding the transcendental relationship between Radha and Krishna which is completely pure.
“The transcendental goddess Srimati Radharani is the direct counterpart of Lord Sri Krishna. She is the central figure for all the goddesses of fortune. She possesses all the attractiveness to attract the all-attractive Personality of Godhead. She is the primeval internal potency of the Lord.” Chaitanya Charitamrita Adi 4.83