Evidence suggests that participating in geek pop culture (e.g. fandoms, digital gaming, live action role playing, board gaming, etc.) can enhance women's interest in STEM by increasing their STEM-related efficacy. This study proposed that this effect hinges on the type of social experiences that women have in geek culture. Inclusive experiences were expected to enhance STEM-related efficacy, while experiences of hostile sexism in these spaces were expected to diminish STEM-related efficacy. An online survey of both U.S. MTurk users (N = 77) and undergraduate students (N = 172) under the age of 30 demonstrated that inclusive experiences and STEM-related efficacy does serially mediate the effect of geek culture engagement on interest in STEM careers. A second model examining the indirect effect of geek engagement on STEM career interest through hostile sexism and STEM-efficacy was not significant. These findings underscore the broader implications of creating a welcoming environment for women in geek culture. They also suggest that women who experience hostile sexism in geek culture and continue to participate might have a general tolerance of toxic geek masculinity.