<p>According to social learning theory, individuals’ behaviors are easily influenced by others, especially intimate others. This effect of intimate relationships has also been observed in pro-environmental behaviors (PEB), defined as “vicarious moral self-regulation.” However, little is known about its underlying mechanisms. Therefore, the present study adopted an event recall description task and a green purchasing task to examine the effect of intimate relationships (i.e., family, loved ones, and oneself) on the PEB of college students (Study 1, <i>N</i> = 96) and to further explore the mediating effect of impression management motivation (Study 2, <i>N</i> = 176). Results showed that participants who recalled the environmentally friendly or unfriendly behaviors of loved ones or themselves made fewer green purchasing choices than those who recalled environmentally neutral behaviors. However, these vicarious licensing and identity effects were not observed when participants recalled the environmental behaviors of family members. Moreover, participants in public (vs. anonymous) situations showed higher impression management motivation and exhibited more green purchasing behaviors, with impression management motivation playing a significant mediating role. The findings suggest that romantic, rather than family, relationships had a negative effect on college students’ PEB, showing vicarious licensing and identity effects. They also indicate that publicizing close friends’ environmental behaviors could stimulate impression management motivation, thereby mitigating this negative effect. These findings enhance understanding of how individual PEB is affected by external intimate relationships and intrinsic impression management motivation.</p>