For many children in Flanders, Belgium, the language of instruction is not their first language. Allowing children to use their heritage languages in the classroom has been argued to have functional and socioemotional benefits. In two exploratory studies, we introduced a multilingual task in four classrooms across three linguistically and socially diverse primary schools, where Dutch was the language of instruction, to determine how students experience the opportunity to use their linguistic repertoire in class. The multilingual task was preceded by an assessment of students' emotional reactions to the languages they speak through the Self-Assessment Manikin gauging students' emotional responses (pleasure, arousal, and dominance), and followed by a semistructured interview on students' language choices. Both studies yielded similar results. Students generally indicated that they felt happy, calm, and in control when speaking their heritage language. Despite these positive assessments, many students refrained from using their heritage language in the multilingual tasks. A qualitative analysis revealed a variety of language-related reasons leading to linguistic insecurity, language anxiety, and not using the heritage language: perceived language proficiency, language norms, language status, and appropriate contexts for language use. Conversely, we also identified several students who felt proud to showcase their heritage language. While multilingual tasks have the potential to induce positive emotions in students, teachers need to be aware of potential backlash and prepared to navigate the negative emotions surrounding contested language choices.