Interpersonal sensitivity is a trait characterized by a hypersensitivity to criticism and rejection. The present author aimed to conceptualize the relationship between interpersonal sensitivity and well-being through the lens of self-determination theory. It was hypothesized that relatedness variables (satisfaction, dissatisfaction, and thwarting) would mediate the relation between interpersonal sensitivity and a novel motivation construct ("motivation for relationship engagement"); it was also hypothesized that motivation would in turn mediate the relation between relatedness variables and positive and negative affect. After 343 university students responded to the online survey, parcels were created to approximate each latent variable. Data were analyzed via structural equation modeling using Mplus Version 7.4, and indices of model fit (Hu & Bentler, 1999) suggested the theoretical model offered a good fit to the data. In support of the author's hypotheses, all direct and indirect paths in the partially mediated structural model were significant (p > .05). Interestingly, findings suggest participants did not discriminate between relatedness dissatisfaction and relatedness thwarting, breaking from past research which had found these constructs to be distinct (e.g., Costa, Ntoumanis, & Bartholomew, 2015). Overall, the present study points to importance of relatedness and motivation as crucial and understudied mediators when it comes to researchers' and clinicians' understanding of interpersonal sensitivity and affective experiences.