Phone use during face-to-face interactions has become increasingly common in adolescents’ social lives, but the mechanisms through which the behavior is associated with adolescents’ socioemotional wellbeing remain understudied. Drawing on the frameworks of digital social multitasking (DSMT) and digital stress, this study examined whether and how three types of digital stress (availability stress, connection overload, and fear of missing out) mediated the association between phone use in friendships and socioemotional wellbeing (depressive symptoms and friendship quality) among adolescents. A sample of 517 adolescents (Mage = 14.83, SD = 1.93) completed an online survey. Results showed that phone use during face-to-face interactions with a friend (i.e., DSMT) had an indirect relationship with greater depressive symptoms through all three types of digital stress. It also had an indirect relationship with better friendship quality via fear of missing out. The paths involving connection overload was moderated by the seriousness of the face-to-face interactions—in more serious interactions, DSMT had an indirect relationship with depressive symptoms, but not friendship quality; in less serious interactions, DSMT had an indirect relationship with friendship quality, but not depressive symptoms. Theoretical and practical implications are discussed.