SB 11.17.33
strinam niriksana-sparsa-
samlapa-ksvelanadikam
pranino mithuni-bhutan
agrhastho ’gratas tyajet
Translation:
Those who are not married — sannyasis, vanaprasthas and brahmacaris — should never associate with women by glancing, touching, conversing, joking or sporting. Neither should they ever associate with any living entity engaged in sexual activities.
Purport:
Praninah indicates all living entities, whether birds, bees or human beings. Among most species of life, sexual intercourse is preceded by diverse mating rituals. In human society, all types of entertainment (books, music, films) and all places of amusement (restaurants, shopping centers, resorts) are designed to stimulate the sexual urge and create an aura of “romance.” One who is not married — a sannyasi, brahmacari or vanaprastha — should rigidly avoid anything related to sex and of course should never see any living entity, whether bird, insect or human, engaging in the various phases of sexual intercourse. When a man jokes with a woman, an intimate, sexually charged atmosphere is immediately created, and this should also be avoided for those aspiring to practice celibacy. Even a householder who becomes attached to such activities will also fall down into the darkness of ignorance.