<jats:p> Abstract. This multistudy investigation examines how entrapment, which is the guilt, anxiety, or stress to respond and be available to others via mobile devices, shapes and is shaped by patterns of mobile use. Using structural equation modeling on cross-sectional survey responses, Study 1 (N = 300) tested relationships among offline social network size, voice and text frequency, entrapment, and well-being. Offline social network size was associated with text message frequency, and both were indirectly associated with lower subjective well-being via entrapment. Study 2 used experience sampling to confirm associations among entrapment, texting, and well-being. Participants (N = 112) reported on face-to-face, phone, and text interactions five times a day for 5 consecutive days (n = 1,879). Multilevel modeling results indicated that beginning-of-week entrapment was associated with more interactions with acquaintances and strangers, and with reporting lower affective well-being and relatedness when interacting via text. Well-being reported during text interactions and number of interactions with acquaintances and strangers during the week both predicted changes in entrapment by the week’s end. Change in entrapment was associated with lower subjective well-being at the week’s end. Results suggest that entrapment is associated with using texting to maintain larger networks of social relationships, potentially stressing individuals’ capacity to maintain less close relationships via mobile communication. </jats:p>