A law has been proposed that would ban the words “father” and “mother” from all official documents in France.

The move comes as part of an effort to legalize same-sex marriage in France. “Father and mother” would be replaced by the gender-neutral term “parents” in all French laws and official documents.

Opponents worry it could lead to the legalization of polygamy or even incest–which is understandable, considering once marriage has been redefined to ignore gender, there is little logically to stop it from being redefined to ignore other boundaries that may currently exist.

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