In Brussels, the officially bilingual (Dutch-French) yet effectively multilingual capital of Belgium, transnational and multilingual families are becoming less and less exceptional. After a brief introduction to the linguistic situation in Brussels and Belgium, this paper discusses the language practices of three multilingual families from different (linguistic) backgrounds, living in and around Brussels. The findings illustrate how these families, regardless of their linguistic background, develop ways of interacting with each other that are far more dynamic and flexible than what they themselves claim to be doing. As a result, the linguistic makeup of these families is more complex and multifaceted than how it is presently being categorized by society.