The Brazilian public notary who granted the trio all of the legal benefits of marriage has set off a firestorm. Claudia do Nascimento Domingues is defending her move, calling the three a "polyfidelitous union."
The relationship involves three professionals in their 30s who live together and say they love one another as equals and are like any other non-married cohabiting couple, CNN reports. They have not been identified.
Some, including religious groups and legal scholars, say the union is not valid and would be the beginning of a slippery slope.
"This union is void of any legality," said Regina Beatriz Tavares da Silva, head of the family law committee of a lawyers' association in Sao Paulo, Brazil.
Brazilian law defines marriage as a union between two people, so it is impossible for a civil union of three to be granted the rights of a marriage of two.
"It goes directly against the constitution," da Silva told CNN. "Monogamy is defined as relations between two, not three or four or five."
Domingues however says the three deserve some benefits. They live together in Rio de Janeiro, they share a bank account, and they want protection in case of separation or death, she told CNN.
Other polyfidelitous groups have reached out to her seeking the same civil union status.
Domingues is studying the cases of a quintet (two men and three women) and another trio (one woman and two men).
