Prior research has highlighted the close relationships between co-founders, sometimes even referring to them in spousal or family-like metaphors. Although prior research has shown how entrepreneurial teams form in terms of co-founder characteristics and search process, we still lack a more nuanced understanding how relationships among entrepreneurial team members form and evolve when they start working together. To explore how relationships in entrepreneurial teams form and evolve, we use a qualitative, inductive research design and draw on data from ten newly formed entrepreneurial teams working in a university incubator. Taking a relational capital perspective, we identify two pathways of relationship development (spiraling and steady pathways) that are contingent on teams’ initial growth aspirations. Our data reveal that non-family teams can develop spousal-like relationships (i.e., love, intimacy, high relational capital) when they have high growth aspirations, go through emotionally charged team member exits, engage in unfiltered communication, and work intimately as a dyad. Counterintuitively, our study shows that high relational capital develops when teams first prioritize and fully commit to their ventures, rather than to team member relationships. We discuss implications for research on relational capital, emerging entrepreneurial team dynamics and team size. Keywords: Emerging entrepreneurial teams, relational capital, growth aspirations, new venture success, team size