The gopi’s are the internal energy of the Lord and can never belong to any other living being.
“Because the gopīs loved Kṛṣṇa exclusively, Yoga-māyā protected their relationship with the Lord at all times, even though they were married. Śrīla Viśvanātha Cakravartī quotes from the Ujjvala-nīlamaṇi as follows:
māyā-kalpita-tādṛk-strī śīlanenānusūyubhiḥ
na jātu vrajadevīnāṁ patibhiḥ saha saṅgamaḥ
“The gopīs’ jealous husbands consorted not with their wives but with doubles manufactured by Māyā. Thus these men never actually had any intimate contact with the divine ladies of Vraja.” The gopīs are the internal energy of the Lord and can never belong to any other living being. Kṛṣṇa arranged their apparent marriage to other men simply to create the excitement of parakīya-rasa, the love between a married woman and her paramour. These activities are absolutely pure because they are the Lord’s pastimes, and saintly persons since time immemorial have relished these supreme spiritual events.”
Source:A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Tenth Canto, Chapter 33 – Text 37