The term heteronormativity refers to the fact that heterosexual individuals are considered natural, which constitutes a source of discrimination against people who differ from the heterosexual norm. As educational institutions can potentially foster children’s internalization of heteronormative representations, there is a great need for new teaching concepts that raise students’ awareness of this issue from an early age on. Authentic literature has proven to be a significant starting point for in-depth reflections on social concerns such as heteronormativity. Hence, this master thesis argues for the use of the picture book And Tango Makes Three (Richardson & Parnell, 2005) to address family diversity in the lower secondary EFL classroom. Based on a true story, this picture book features the gay penguin couple Roy and Silo who hatch another penguin couple’s egg and raise the chick Tango as their own child. A teaching sequence comprising five lessons on And Tango Makes Three was conducted in the first grade of an Austrian middle school. Lesson observations, students’ creative writing products, and results of the questionnaire suggest that this picture book is not only suitable to promote EFL beginners’ reading competences and joy of reading but also to counter heteronormativity by enabling students to reflect on family diversity.