The integration of external and internal bodily signals provides a coherent, multisensory experience of one's own body. The ability to accurately detect internal bodily sensations is referred to as interoceptive accuracy (IAcc). Previous studies found that IAcc can be increased when people with low IAcc engage in self-processing such as when looking in the mirror or at a photograph of one's own face. However, the way the self is represented changes depending on the context. Specifically, in social situations, the self is experienced in relation to significant others and not as an isolated individual. Intriguingly, in a relational context romantic partners can be used as social mirrors for one's self. We here investigated whether directing one's attention to romantic partners would enhance one's IAcc, similar to the effect of self-face observation when the self is processed in isolation. During a heartbeat counting task, both concurrent self-face and partner-face observation improved accuracy in those with initially low IAcc; however, this improvement was significantly greater for the partner's face. These results suggest that significant others may play an important role in determining the quality of one's self-awareness. Given that high interoceptive awareness is linked to better emotion regulation, increased IAcc during partner observation is likely to have an adaptive role in maintaining stable and secure romantic relationships through greater emotion regulation.