High Quality Content by WIKIPEDIA articles! In cultures that practice marital monogamy, bigamy is the act of entering into a marriage with one person while still legally married to another. Bigamy is a crime in most western countries, and when it occurs in this context often neither the first nor second spouse is aware of the other. In countries that have bigamy laws, consent from a prior spouse makes no difference to the legality of the second marriage, which is usually considered void.