The Call of the Flute.

tā vāryamāṇāḥ patibhiḥ

pitṛbhir bhrātṛ-bandhubhiḥ

govindāpahṛtātmāno

na nyavartanta mohitāḥ

Their husbands, fathers, brothers and other relatives attempted to stop them, but Kṛṣṇa had already stolen their hearts. Enchanted by the sound of His flute, they refused to turn back.

(Some of the young Gopīs were married, and their husbands tried to stop them. The unmarried girls had to deal with their fathers and brothers and other relatives. None of these relatives would have ordinarily allowed the Gopikas to go alone into the forest at night, but Lord Kṛṣṇa had already engaged His internal potency, and thus the entire romantic episode unfolded without hindrance).

* Aside from the literal, layers of meaning are to be found within this shlok. The Call of the flute is the considered the call of the divine, only particular souls can hear this sound, and only those Gopis who were qualified and the Lord had chosen could hear this sound. This sound called them to come and meet the Lord in the dead of the night, the Lord called them for the ultimate union, The Raas Lila. Pages of literature have been written on Raas Lila, and I will not attempt the delve into this lila at present, the Lila is not easily comprehended. However, fundamentally the Rasa Lila represents the highest form of communion with the divine, it is the meeting of the divine and the jiv/soul. The husbands and sons represent material attachment that the Gopis left, they left everything and ran to the Lord. They were so lost in love for their beloved that nothing could stop them at this point. This is the last hurdle we all must pass, when the Lord calls we must leave all attachment, all dignity, all doubt and run. This is the last instruction the Lord gives in the Bhagavad Gita. 

** As stated above Lord Krsna desired to reward them for their love, and thus used his Maya to keep the husbands at peace so the family life of the Gopis would go unhindered. The running to the Lord can be taken in a two main ways. Either we literally renounce and leave everything behind, and enter into his holy land as renunciants; or in the vein that we still engage in worldly matters, not leaving our families behind, but in the dead of night, (i.e within the inner recesses of our mind and heart), we should dance with the divine, and worship Sri Krsna, that beauteous dark Lord.