The current research evaluated individual differences and contextual effects on men’s robust sexual overperception bias and on women’s tendency to be misperceived. Study 1 pioneered the use of a “speed-meeting” methodology which allowed for a direct calculation of sexual misperception by comparing measures of actual interest to measures of estimated interest across five interactions. As predicted, men demonstrated a robust sexual over-perception bias, a bias that was influenced by their mating strategy and physical attractiveness. Women, on the other hand, consistently underestimated men’s sexual interest in them, and physical attractiveness was a key predictor of their likelihood of being overperceived. Study 2 replicated the prediction tests from Study 1 and narrowed down the exploratory regression models to the most specific and robust effects, namely mating strategy and physical attractiveness. Study 3 examined the effects of testosterone (T) on men’s sexual misperception by manipulating intrasexual competition in the lab. Men engaged in a computer game, which randomly assigned them to win or lose, against an unseen male competitor. After the game, each participant interacted with a trained female confederate posing as a participant, after which they rated her on multiple traits, including interest in her and his estimate of her interest in him. Salivary assays for T were collected before and after the game, and after interacting with the confederate. The results of the experiment demonstrated that although the competition outcome did not affect men’s T, changes in T during the interaction with the woman predicted men’s sexual misperception. The more attractive the man found her, and the more interested he was in her, the more his T increased during their interaction and the more he overperceived her interest. Taken together, these studies indicate that far from a simple sex difference, men’s overperception bias is predictably nuanced and specific. / text