Effectively engaging students in mathematics discourse is challenging, especially in a language other than the one in which you learned mathematics. Teachers must manage the academic as well as social function of language. In Spanish-English bilingual classrooms in the U.S., changing the language of instruction to Spanish may not be enough to disrupt entrenched patterns of mathematics participation, resulting in continued marginalization of Latino students. In this article, I describe what our bilingual pre-service teachers (BPST) learned through a mathematics methods class taught in a fifth-grade classroom of a local, urban, bilingual immersion elementary school. I reflect on my experience as a bilingual mathematics teacher educator and analyze BPST reflections on their successes and challenges as they learned to lead mathematics discussions in Spanish while developing attention to power dynamics among their students. Through the field experience, BPST became more comfortable with academic vocabulary in mathematics and using techniques to involve many students in the discussion. Yet they struggled with explicitly positioning Latino bilingual students as important mathematical thinkers in a classroom in which White, English-dominant students tended to participate most in mathematics discussions. Implications for bilingual teacher education include the need to support bilingual teachers in developing academic Spanish for mathematics as well supporting BPSTs to notice and manage power issues related to language, race, and mathematical competence during mathematics discussions.