Sexuality in secure mental healthcare has been overlooked in both clinical praxis and academic research. In the UK, there exist no formal policies to inform staff approaches to managing inpatient sexuality. The limited research that has been undertaken in this field has found that often, prohibitive approaches are favoured, which may affect how inpatients conceptualise and experience their sexuality in the long-term. The aim of this study was to identify discursive constructions of inpatient sexuality, as articulated in semi-structured group interviews with inpatients and ward staff from a secure mental healthcare facility in England. The analysis identified constructions of inpatient sexuality within two overarching and conflicting discourses: one of the normalcy and legitimacy of sexual expression in human experience; and the other of risk, wherein sexuality needed to be regulated and obstructed. Inpatients' expressions of sexuality could often only be conceptualised in terms of 'organisational misbehaviour', acts that violated the implicit norms and codes of the institution. It is suggested that recoding inpatient sexuality as misbehaviour could have implications for inpatients' long-term recovery.