Focusing on children's play, the present article explores how 3- to 6-year-old children (re)produce, (re)negotiate and challenge heteronormativity in a Swedish Early Childhood Education setting. The article is based on ethnographic data, focusing on (re)production of heteronormativity in a particular kind of idealized, often feminine-coded and peer-group play with a low degree of teacher participation, labelled 'Mum, Dad, Child play' by the children. Our results show that children's play is structured by certain themes, such as family and home, and certain gendered and/or age-coded positions, such as mother, father, child or baby. Age difference (child/adult) proves to be the cornerstone of the heteronormative family metaphor of the play, where the child/baby position is central. To describe the intersections of age, gender and sexuality in our analysis, we suggest the use of the concept of "age-coded heteronormativity."