How should we expect growing understandings of the nature of mathematical practice to inform classroom mathematical practice? We address this question from a perspective that takes seriously the notion that mathematics education, as a societal enterprise, is accountable to multiple sets of stakeholders, with the discipline of mathematics being only one of them. As they lead instruction, teachers can benefit from the influence of understandings of mathematical practice but they also need to recognize obligations to other stakeholders. We locate how mathematics instruction may actively respond to the influence of the discipline of mathematics and we exemplify how obligations to other stakeholders may participate in the practical rationality of mathematics teaching as those influences are incorporated into instruction.