When young adults are asked to either think of an opposite-sex friend or bring an opposite-sex friend to the lab, men report much more attraction to their friend than women do (Bleske-Rechek et al. Journal of Social and Personal Relationships, 29: 569-596, 2012; Kaplan and Keys Journal of Social and Personal Relationships, 14: 191-206, 1997). In two studies, we utilized a naturalistic sampling strategy to obtain our friendship dyads. We approached and surveyed male-female dyads who were lounging at a university student center and found that the mean difference between male and female friends' attraction to one another was weak and statistically unreliable. We speculated that the opposite-sex friends that men and women find themselves with in their everyday life might be different from the opposite-sex friends who come to mind when asked by researchers to think of their friends. Men's and women's mating adaptations, which differ particularly in attention to attractiveness and proclivity toward shortterm sex, might be reflected in how men and women conceptualize opposite-sex friends; hence, previous studies may have documented a stronger sex difference in attraction because men and women in those samples had different types of people in mind when they thought about opposite-sex friends. To test that possibility, we asked young adults to "think of an opposite-sex friend" and then choose descriptors for that person. Men less often than women characterized the person as "a friend" and more often than women characterized the person as someone they were "attracted to." We conclude that men's and women's everyday experiences with opposite-sex friends differ from their mental conceptions of opposite-sex friends.