In this paper, we discuss our experience in collaborating with mathematicians to increase their use of active learning pedagogy in a proof-based linear algebra course. The mathematicians we worked with valued using active learning pedagogy to increase student engagement but were reluctant to use active learning pedagogy due to time constraints. Our mathematicians perceived obligations in their teaching that increased the time it would take to implement some of the active learning pedagogy that we suggested, leading them to view this pedagogy as inviable. By attending to mathematicians' obligations, we were able to design active learning strategies that met the interests and needs of the mathematics educators and mathematicians collaborating on this project.