It is quite clear that according to Vedic culture a woman who accepts a paramour or second husband in the presence of the husband she has married is certainly responsible for the degradation of her father's family and the family of her husband. The rules of Vedic culture in this regard are strictly observed in the respectable families of brahmanas, ksatriyas and vaisyas even today; only the sudras are degraded in this matter. For a woman of the brahmana, ksatriya or vaisya class to accept another husband in the presence of the husband she has married, or to file for divorce or accept a boyfriend or paramour, is unacceptable in the Vedic culture.

From Srila Prabhupada's purport to SB 9.3.21