Sex life

 Sex life is meant only for begetting Krsna conscious children

Another significant point of this verse is that one has to observe the prescribed rules and regulations. As confirmed in Bhagavad-gita, yuktahara-viharasya. When one engages in devotional service in Krsna consciousness, he still has to eat, sleep, defend and mate because these are necessities of the body. But he performs such activities in a regulated way. He has to eat krsna-prasada. He has to sleep according to regulated principles. The principle is to reduce the duration of sleep and to reduce eating, taking only what is needed to keep the body fit. In short, the goal is spiritual advancement, not sense gratification. Similarly, sex life must be reduced. Sex life is meant only for begetting Krsna conscious children. Otherwise, there is no necessity for sex life. Nothing is prohibited, but everything is made yukta, regulated, with the higher purpose always in mind. By following all these rules and regulations of living, one becomes purified, and all misconceptions due to ignorance become nil. It is specifically mentioned here that the causes of material entanglement are completely vanquished.

Srila Prabhupada — SB 3.33.26, purport