COVID-19-related social lockdowns had profound consequences in all aspects of social life, yet technology’s role in mediating relationships during lockdown has received little attention. Drawing on a survey of 565 young adults in the UK, we used mixed methods to explore (a) differences in technology use by people in serious romantic relationships (cohabiting vs. living apart together), casual relationships or single; and (b) how COVID-19 influenced long-term, serious relationships. For participants in a serious relationship, technology was used as a strategy to facilitate ongoing communication, enabling partners to achieve ‘intimacy from afar’. Qualitative analysis revealed five reasons (more free time, navigating lockdown restrictions, greater boredom, desire for love and miscellaneous) for online dating profile usage changes. People in serious relationships perceived deeper intimate bonds, boundary issues, less physical intimacy, difficulty with lockdown separation and greater negative impact because of COVID-19. Limitations and implications are discussed.