This question was raised by Parīkṣit Mahārāja when Śukadeva Gosvāmī described the rāsa-līlā. So that... "Kṛṣṇa appeared on this material world, dharma-saṁsthāpanārthāya, paritrāṇāya sādhūnām (BG 4.8), dharma-saṁsthāpanārthāya. So why He violated these rules of dharma?" Violation because, according to Vedic civilization, nobody can mix with other's wife or other woman. Even in moral principle, as Cāṇakya Paṇḍita said, mātṛvat para-dāreṣu. "All women should be treated just like mother." Not like the present society. Formerly, every woman should be addressed as "mother," Mātājī. And now they have invented "Bahinjī." No. Woman should be addressed as "mother." Mātṛvat para-dāreṣu.
So this question was put forward by Parīkṣit Mahārāja before Śukadeva Gosvāmī, "How Kṛṣṇa danced with others' wives and sisters, like that?" This is against principle of dharma. So just to clear the position of Kṛṣṇa... Kṛṣṇa is personally said, personally saying also, and this is confirmed by Śukadeva Gosvāmī that tejīyasāṁ na doṣāya (SB 10.33.29). Kṛṣṇa cannot be polluted.