Background: HIV prevention for men who have sex with men (MSM) has typically focused on behaviour change at the individual-level, rather than as part of a couple. However, recent research has highlighted the role of primary sexual partners in the transmission of HIV among young MSM in the US, estimating that as many as 84% of new transmissions were from men’s main partner. This suggests that work with couples could contribute to prevention efforts. Methods: We conducted qualitative in-depth interviews with 30 young MSM (aged 18-29) in Scotland, recruited via a number of strategies; online advertisements, through voluntary sector organisations working with MSM, and snowballing. Thematic data analysis focused on identifying how men understand HIV risk management strategies in the context of relationships, speciﬁcally the role of ‘safer sex’ practices, HIV testing, and expectations around monogamy and/or sexual exclusivity. Results: At the time of interview, nine men reported being in a relationship, and the majority (n=28) discussed their aspirations for sex in long-term relationships. Participants’ demonstrated varying levels of HIV literacy (i.e. HIV-related knowledge and an individual’s capacity to apply this), and although all discussed condom use as part of ‘safer sex’ and their individual management of HIV risk, a recurring theme was desire to discontinue condom use in the context of a committed relationship. Over a third of the men (n=22) discussed discontinuing condom use in this context. Of those in relationships, six had discontinued condom use, but not all tested for HIV prior to this, nor explicitly discussed expectations for monogamy and/or sexual exclusivity with their partners. Agreeing to testing and discussing expectations of ﬁdelity were complicated by issues of trust and intimacy. Conclusion: How MSM understand and manage HIV risk in relationships has implications for future HIV prevention. Knowledge of their own (and partner’s) HIV status - particularly where serodiscordant relationships are identiﬁed -could enable men to make decisions around prevention, and where appropriate, open up the possibility of accessing biomedical prevention. Our research suggests young MSM in relationships continue to base safer sex decisions on perceptions of ﬁdelity and trust in their partners. Young MSM accessing testing in clinical settings could be targeted for interventions to encourage HIV status disclosure and informed safer sex negotiation.