How accurately do romantic partners perceive each other’s sexual advances? Two preregistered studies investigated whether perceivers over- or underestimate the specific behaviors their partner uses to indicate sexual interest (directional bias), as well as correctly detect the particular pattern of those behaviors (tracking accuracy). We also tested if biased and accurate perceptions were moderated by gender and explored how bias and accuracy predicted relational outcomes. Results revealed strong evidence for tracking accuracy in judgments of sexual advances overall, and mixed results for directional bias. Gender moderated only directional bias, such that women consistently overestimated their partner’s sexual advances, whereas men underestimated or showed no bias. Finally, biased sexual advance perceptions were associated with sexual satisfaction and love for both perceivers and partners. Implications for relationship functioning are discussed.