Srimad Bhagavatam Canto 07, Chapter 12, Text 09

SB 7.12.9

nanv agnih pramada nama
 ghrta-kumbha-samah puman
sutam api raho jahyad
 anyada yavad-artha-krt
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Woman is compared to fire, and man is compared to a butter pot. Therefore a man should avoid associating even with his own daughter in a secluded place. Similarly, he should also avoid association with other women. One should associate with women only for important business and not otherwise.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
If a butter pot and fire are kept together, the butter within the pot will certainly melt. Woman is compared to fire, and man is compared to a butter pot. However advanced one may be in restraining the senses, it is almost impossible for a man to keep himself controlled in the presence of a woman, even if she is his own daughter, mother or sister. Indeed, his mind is agitated even if one is in the renounced order of life. Therefore, Vedic civilization carefully restricts mingling between men and women. If one cannot understand the basic principle of restraining association between man and woman, he is to be considered an animal. That is the purport of this verse.
Srimad Bhagavatam Canto 07, Chapter 12, Text 08
Srimad Bhagavatam Canto 07, Chapter 12, Text 10