Srimad Bhagavatam Canto 09, Chapter 06, Text 51

SB 9.6.51

sangam tyajeta mithuna-vratinam mumuksuh
 sarvatmana na visrjed bahir-indriyani
ekas caran rahasi cittam ananta ise
 yuñjita tad-vratisu sadhusu cet prasangah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
A person desiring liberation from material bondage must give up the association of persons interested in sex life and should not employ his senses externally [in seeing, hearing, talking, walking and so on]. One should always stay in a secluded place, completely fixing his mind at the lotus feet of the unlimited Personality of Godhead, and if one wants any association at all, he should associate with persons similarly engaged.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Saubhari Muni, giving conclusions derived from his practical experience, instructs us that persons interested in crossing to the other side of the material ocean must give up the association of persons interested in sex life and accumulating money. This is also advised by Sri Caitanya Mahaprabhu:
 
niskiñcanasya bhagavad-bhajanonmukasya
 param param jigamisor bhava-sagarasya
sandarsanam visayinam atha yositam ca
 ha hanta hanta visa-bhaksanato ’py asadhu
 
(Caitanya-candrodaya-nataka 8.27)
 
“Alas, for a person seriously desiring to cross the material ocean and engage in the transcendental loving service of the Lord without material motives, seeing a materialist engaged in sense gratification and seeing a woman who is similarly interested is more abominable than drinking poison willingly.”
 
One who desires complete freedom from material bondage can engage himself in the transcendental loving service of the Lord. He must not associate with visayi — materialistic persons or those interested in sex life. Every materialist is interested in sex. Thus in plain language it is advised that an exalted saintly person avoid the association of those who are materially inclined. Srila Narottama dasa Thakura also recommends that one engage in the service of the acaryas, and if one wants to live in association, he must live in the association of devotees (tandera carana sevi bhakta-sane vasa). The Krsna consciousness movement is creating many centers just to create devotees so that by associating with the members of such a center people will automatically become uninterested in material affairs. Although this is an ambitious proposal, this association is proving effective by the mercy of Sri Caitanya Mahaprabhu. By gradually associating with the members of the Krsna consciousness movement, simply by taking prasada and taking part in chanting of the Hare Krsna mantra, ordinary persons are being considerably elevated. Saubhari Muni regrets that he had bad association even in the deepest part of the water. Because of the bad association of the sexually engaged fish, he fell down. A secluded place is also not secure unless there is good association.
Srimad Bhagavatam Canto 09, Chapter 06, Text 50
Srimad Bhagavatam Canto 09, Chapter 06, Text 52