The story about Brahmacarya of Bhagavan Shree Krishna can be encountered in "Gopala-Tapani-Upanishad", "Garga-Samhita" and in the Darshans of Vaishnava-Acharyas and Saints, but the majority of people still does not know it.
This story is Upanishadic and it is very significant for understanding the real character of REAL Shree Krishna.
And the REAL Krishna is Acintya-ParaBrahman, but not an ordinary boy, who steals butter in Vrindavan.
One should learn by heart, that in reality Shree Krishna does not need Rasa-Leela at all and that in reality Shree Krishna is Maha-Tyagi. (amendment 21:59 03.07.2013 - actually, Shree Krishna is not only Maha-Tyagi, but Maha-Bhogi too and my words about Bhagavan Shree Krishna, Who does not need Rasa-Leela are false, because Bhagavan Shree Krishna is EkaRasa and Bhagavan Shree Krishna unifies even the most contradictory traits in His Own Person - this Siddhanta is discussed in "Satwata-Tantra" and in "Shree Vishnu-Purana").
I will dwell on 2 variants of this story.
The first variant is from "Gopala-Tapani-Upanishad", the second one is from Madhurya-Khanda of "Garga-Samhita".
The third part of this article will be entirely dedicated to the purport of this story by Purna Purushottama Shree Shreemad NarayanSwami from "Vachanamrita" ("Vachanmrut").
The following are the verses from "Gopala-Tapani-Upanishad" and the words of Shree Sheemad Durvasa Muni need special heed here and, speaking from the deep of the heart, these words should be memorized and ought to be contemplated upon every day.
There is a mayavadic verse (40) in this part of "Gopala-Tapani-Upanishad", it is for the deception of demons, so one can just ignore it.
1. Once the passionate cowherd women of Vraja spent the night with the cowherd Krishna, who is the Supreme Lord of all. In the morning, they engaged in a conversation with him as follows: