In this article, it is argued that the tale of Filippo Balducci in Decameron, Day IV, by Boccaccio, serves as a meta-meditation on the relationship between the control of language and sexual behaviour. It is suggested that the 101st novella is part of the framework narrative where Boccaccio articulates his linguistic policy on sexual metaphor. The results show that the ending of the tale both can be found in the ‘successful’ sexual metaphors employed by Boccaccio in his text, and in the discussions on sexual language that comprise the Conclusion to the work.