There is a growing scholarly consensus in favor of family autonomy. Marriage is an institution steeped in inequality. People should be able to form other types of families. But while scholars largely agree on this abstract goal, they do not agree on how to promote family choice. Take the issue of economic rights for nonmarital partners. The conventional doctrine treats nonmarital partners as legal strangers. The dominant scholarly defense of this rule sounds in the register of autonomy. The current rule, scholars argue, vindicates the choice to reject marriage. By carefully mining the law of nonmarital parentage, this Article demonstrates that the conventional doctrine undermines rather than furthers family autonomy.