In the current research, we investigated perceptual accuracy in romantic partners’ detection of sexual rejection. In two daily diary studies of predominantly cisgender heterosexual couples, we examined patterns of accuracy and bias concerning both the degree of sexual disinterest (Study 1; N = 98 couples) and occurrence of sexual rejection (Study 2; N = 115 couples), as well as how these perceptions were associated with satisfaction. Using a multi-method approach to capture both continuous and categorical operationalizations of sexual rejection (Study 1: truth and bias; Study 2: quasi-signal detection), we found that people were both accurate and biased in their perceptions of partner rejection. Across studies, results showed that people demonstrated general tracking accuracy in detecting a partner’s sexual rejection, but they also overestimated the degree and occurrence of this rejection. Additionally, this overestimation bias was associated with lower daily relationship and sexual satisfaction. Overall, our findings highlight the importance of dyadic perceptions of sexual rejection in shaping daily relationship and sexual functioning.