This study focuses on the interface between bidialectism and bilingualism and provides empirical support for the call for language educators to be trained in issues relating to linguistic variation. Drawing on the sociolinguistic setting of Cyprus, the study investigates the linguistic behaviour of bidialectal teachers in the English foreign-language classroom. The findings reveal that, despite the popular belief that the standard variety of the first language (Standard Modern Greek) is used alongside English, the Greek Cypriot dialect is, in fact, more prevalent. Teachers use the regional dialect in a consistent and circumstance-dependent manner. However, they express surprise and embarrassment when told about their linguistic behaviour. Language teacher training in linguistic variation may convey distinct advantages in educational contexts where bidialectism and bilingualism meet. Sociolinguistically informed training which celebrates linguistic diversity has the potential to empower teachers to appreciate and make use of all the linguistic varieties available to them.