Based on empirical, qualitative research on 'social mixing' in multi-ethnic London schools, this article argues for a conceptualisation of social mixing as an exchange of the self. Through analysis of three working-class, minority ethnic students who attempt to 'cross borders' into White middle-class subcultures, I explore the differing capital value embodied in their raced, classed and gendered identity positions. Friendships across this border are characterised by 'semi-investments' on both sides, and promise only partial possibilities for social mobility via social mixing, through limited access to academic capital and embodied Whiteness.