LGBT movements are supported unanimously, sexual relationships with people other than an opposite-sex spouse undermines the traditional family and opponents say legalization of same-sex marriage will open the door for the legalization of polygamy which is marrying more than one person.
Some social conservatives believe that all sexual relationships with people other than an opposite-sex spouse undermines the traditional family and that children should be reared in homes with both a father and a mother. Opponents say same-sex relationships are not marriages, that legalization of same-sex marriage will open the door for the legalization of polygamy, that it is unnatural and that it encourages unhealthy behavior. Polygyny (/pldni/; from Neoclassical Greek  from - poly- "many", and gyne "woman" or "wife") is the most common and accepted form of polygamy, entailing the marriage of a man with several women. 
