Spousal support can mitigate stress’s impact on daily functioning and neural responses to stressors. However, the effectiveness of spousal support in reducing stress may be moderated by gender. The present study investigated the impact of observer presence in 66 heterosexual married couples, specifically a spouse or a confederate, on two neural indices of performance monitoring: early error detection (error-related negativity [ERN]) and later error awareness (error positivity [Pe]). Contrary to predictions, ERN was consistently smaller in observed conditions, suggesting that being observed, irrespective of the observer’s identity, diminished attention to errors. Notably, only women exhibited an enhanced ERN in the presence of their spouse, suggesting gender-specific differences in neural responses to spousal support during performance monitoring. Pe was larger when completing the task in the presence of a spouse and men displayed larger Pe than women. The present findings underscore the complex role of social context in performance monitoring, challenging existing assumptions about the uniformity of neural indices of performance monitoring during observation. Findings emphasize the need to dissect the nuanced interplay between observer presence, gender differences, and performance monitoring and offer valuable insights into the social modulation of error processing, particularly in a stressful observation context.