You have got one wife or one husband, and that is also restricted: only for begetting child you can have sex life. So many things. The whole idea is restriction. Not that ‘Because I have got a wife it is a machine for sex life.’ No, no. A marriage mean, that does not mean. Marriage does not mean like that. It is restriction.

From Srila Prabhupada’s lecture on Srimad-Bhagavatam 1.5.9-11 — New Vrindaban, June 6, 1969