This article explores the potential of feminist new materialisms for rethinking enduring debates that cohere around children, sexuality, age and ‘childhood innocence’. A new materialist ontology of sexuality and Karen Barad's concept of spacetimemattering are employed to conceptualise sexuality as an emergent becoming of relational material-discursive forces. Within this paradigm, mobilisation of arguments about ‘sexual innocence and readiness’ become a matter of entanglement of contingent ‘things’, ‘spaces’ and ‘ideas’, that includes young people's own sexual knowledge. We consider how this reorientation shifts the contours, debates and possibilities of sexuality education beyond restrictive ‘age-appropriate’ narratives.