In line with recent critiques of communicative language teaching (Byrnes and Maxim 2004; Byrnes 2006), this paper considers how instances of spontaneous, creative language play can afford access to a range of linguistic practices that are often devalued or ignored in classrooms. To this end, it examines how university students in an advanced Spanish conversation course jointly manipulate linguistic forms, semantic units, and discursive elements for the amusement of themselves and others. The analysis suggests that these humorous moments provide opportunities for new and more varied forms of participation and language use, contributing to the expansion of learners' overall communicative repertoires. That is, it illustrates how co-constructed episodes of unscripted language play can destabilize institutionally-sanctioned assumptions about what counts as a meaningful or legitimate act of language use, momentarily reconfiguring the definition of linguistic expertise and broadening the possibilities for acceptable language use. Following Hall et al. (2006), the authors advocate a view of learners as multicompetent language users (V. Cook 1991, 1992, 1999), whose language knowledge is grounded in the actual linguistic practices in which they engage.