Then as far as dama (self-control) is concerned, it is not only meant for other orders of religious society, but is especially meant for the householder. Although he has a wife, a householder should not use his senses for sex life unnecessarily. There are restrictions for the householders even in sex life, which should only be engaged in for the propagation of children. If he does not require children, he should not enjoy sex life with his wife. Modern society enjoys sex life with contraceptive methods or more abominable methods to avoid the responsibility of children. This is not in the transcendental quality, but is demoniac. If anyone, even if he is a householder, wants to make progress in spiritual life, he must control his sex life and should not beget a child without the purpose of serving Kṛṣṇa. If he is able to beget children who will be in Kṛṣṇa consciousness, one can produce hundreds of children, but without this capacity one should not indulge only for sense pleasure.
(Bhagavad-Gita-------16:1-3-------purport).

A brahmacārī practices celibacy, controlling his sex life. One cannot enjoy unrestricted sex life and practice yoga; this is rascaldom. So-called yogīs advertise that one can go on enjoying as one likes and simultaneously become a yogī, but this is totally unauthorized. It is very clearly explained here that one must observe celibacy. Brahmacaryam means that one leads his life simply in relationship with Brahman, or in full Kṛṣṇa consciousness. Those who are too addicted to sex life cannot observe the regulations which will lead them to Kṛṣṇa consciousness. Sex life should be restricted to persons who are married. A person whose sex life is restricted in marriage is also called a brahmacārī.
(Srimad Bhagavatam------3:28:4-------purport).

The yogic practices in general and haṭha-yoga in particular are not ends in themselves; they are means to the end of attaining steadiness. First one must be able to sit properly, and then the mind and attention will become steady enough for practicing yoga. Gradually, one must control the circulation of vital air, and with such control he will be able to withdraw the senses from sense objects. In the previous verse it is stated that one must observe celibacy. The most important aspect of sense control is controlling sex life. That is called brahmacarya. By practicing the different sitting postures and controlling the vital air, one can control and restrain the senses from unrestricted sense enjoyment.
(Srimad Bhagavatam------3:28:5-------purport).

The word ūrdhva-retasaḥ in this verse is very significant. Ūrdhva-retaḥ refers to one who can control sex life and who instead of wasting semen by discharging it, can use this most important substance accumulated in the body to enrich the brain. One who can completely control sex life is able to work wonderfully with his brain, especially in remembering. Thus students who simply hear Vedic instructions once from their teacher could remember them verbatim without needing to read books, which therefore did not exist in former times.
(Srimad Bhagavatam------5:1:26-------purport).

The climax of the system of varṇāśrama-dharma, or sanātana-dharma, is clearly expressed here in this particular verse of Śrīmad-Bhāgavatam. The highest benefit that can be awarded to a human being is to train him to be detached from sex life, particularly because it is only due to sex indulgence that the conditioned life of material existence continues birth after birth. Human civilization in which there is no control of sex life is a fourth-class civilization because in such an atmosphere there is no liberation of the soul encaged in the material body. Birth, death, old age and disease are related to the material body, and they have nothing to do with the spirit soul. But as long as the bodily attachment for sensual enjoyment is encouraged, the individual spirit soul is forced to continue the repetition of birth and death on account of the material body, which is compared to garments subjected to the law of deterioration.
(Srimad Bhagavatam------2:6:20-------purport).

The Lord was thus engaged in household life for many, many years, but at last His detachment from ephemeral sex life was fully manifested. Even though the Lord is never attached to any kind of material sex life, as the universal teacher He remained a householder for many, many years, just to teach others how one should live in householder life. Śrīla Viśvanātha Cakravartī Ṭhākura explains that the word samajāyata means "fully exhibited." In all His activities while present on the earth, the Lord exhibited detachment. This was fully displayed when He wanted to teach by example that one should not remain attached to household life for all the days of one's life. One should naturally develop detachment as a matter of course. The Lord's detachment from household life does not indicate detachment from His eternal associates, the transcendental cowherd damsels. But the Lord desired to end His so-called attachment to the three modes of material nature. He can never be detached from the service of His transcendental associates like Rukmiṇī and other goddesses of fortune, as described in the Brahma-saṁhitā (5.29): lakṣmī-sahasra-śata-sambhrama-sevyamānam.
(Srimad Bhagavatam------3:22:2-------translation and purport).