This paper asks, what more can we think in relation to debates around young people's use of mobile phones at school? Rather than attempting to answer the question of whether mobile phones are "good" or "bad" for young people, this paper recasts the debate's ontological underpinnings. To do this feminist appropriations of the Deleuzian concept of assemblage and a relational materialist notion of "more-than-human" are drawn on. By recognising sexuality-as-assemblage, it is possible to see more-than-human elements (such as mobile phones) as implicated in the becoming of sexuality at school. This conceptualisation implies new texture and dimensionality to the wider project of (re)producing sexual meanings and identities at school. It also necessitates acknowledging an ontologically different understanding of the human-non-human divide, that decentres young people and/or phones as to "to blame" for "negative" practices like sexting. Instead, agency manifests via the intra-activity that occurs when mobile phones and young people are in-relation.