Srimad Bhagavatam Canto 04, Chapter 29, Text 14

SB 4.29.14

asuri medhram arvag-dvar
 vyavayo graminam ratih
upastho durmadah prokto
 nirrtir guda ucyate
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The city called Gramaka, which is approached through the lower gate of Asuri [the genital organ], is meant for sex, which is very pleasing to common men who are simply fools and rascals. The faculty of procreation is called Durmada, and the rectum is called Nirrti.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
When the world becomes degraded, civilization becomes demoniac, and for the common man the rectum and the genitals are taken very seriously as the centers of all activity. Even in such a sacred place as Vrndavana, India, unintelligent men pass off this rectal and genital business as spiritual activity. Such people are called sahajiya. According to their philosophy, through sexual indulgence one can elevate oneself to the spiritual platform. From these verses of Srimad-Bhagavatam, however, we understand that the desires for sexual satisfaction are meant for the arvak, the lowest among men. To rectify these rascals and fools is very difficult. After all, the sex desires of the common man are condemned in these verses. The word durmada means “wrongly directed,” and nirrti means “sinful activity.” Although this clearly indicates that sex indulgence is abominable and misdirected even from the ordinary point of view, the sahajiyas nonetheless pass themselves off as devotees conducting spiritual activities. For this reason, Vrndavana is no longer visited by intelligent men. We are often asked why we have made our center in Vrndavana. From the external point of view, it can be concluded that Vrndavana has become degenerate due to these sahajiya activities, yet from the spiritual point of view, Vrndavana is the only place where all these sinful persons can be rectified by means of taking birth in the forms of dogs, hogs and monkeys. By living in Vrndavana as a dog, hog or monkey, the living entity can be elevated to the spiritual platform in the next life.
Srimad Bhagavatam Canto 04, Chapter 29, Text 13
Srimad Bhagavatam Canto 04, Chapter 29, Text 15