Evidence suggesting that implicit partner evaluations (IPEs), but not explicit evaluations (EPEs), can predict later changes in satisfaction and relationship status has led researchers to postulate that IPEs must be especially sensitive to relational reward and costs. However, supporting evidence for this assumption remains scarce, and very little is known regarding how IPEs versus EPEs actually update in everyday life. Two studies (one in-lab dyadic interaction study, N = 255, and one 14-day dyadic diary study, N = 348) investigated updating in IPEs and EPEs in the context of real-life relationship experiences. Study 1 revealed that the level of positive and negative experiences that a couple encountered while discussing a divergence of interests in their relationship predicted pre-to-post changes in EPEs, but not in IPEs. Study 2 revealed that IPEs showed less sensitivity to everyday relationship experiences across multiple metrics over the course of 14 days. Specifically, compared with EPEs, IPEs fluctuated less at the within- (vs. between-) person level, showed less-abrupt changes from day-to-day, and had a substantially weaker relationship with same-day positive and negative experiences. Rather than covarying with same-day experiences, IPEs appeared sensitive to relationship experiences aggregated across multiple prior days as well as to highly diagnostic relationship experiences, such as breakup. Consistent with recent advances in social-cognitive research, these findings support a modified account of IPE sensitivity, according to which IPEs show only gradual shifts under everyday circumstances, but more-dramatic shifts under highly diagnostic circumstances. Implications of these findings for close relationships and implicit social cognition research are discussed.