This paper adopts a structural relational approach to the study of emerging boundaries of sexualities. Bisexual category, one that inhabits an unsettled borderland between heterosexual and homosexual category, makes an ideal case to understand how unsettled categories respond to the longstanding analytical, symbolic, and social boundaries of heterosexual/homosexual. I ask three connected research question: (1) What is this emerging boundaries of sexualities? (2) How do bisexual individuals construct membership and navigate boundary disruption, passing, or integration? (3) When are these boundaries erected? Using content analysis of a popular lesbian forum, I first uncover new hierarchies of sexualities constructed through the discourse of “lesbian superiority”. Then, I apply qualitative network analysis to 31 in-depth interviews with bisexual-identified individuals. By innovatively analyzing different network positions of sexual orientations, I discover that these individual’s network positions—in relation to heterosexual, lesbian, and bisexual communities—corresponds to different levels of response to heterosexual- homosexual boundaries. Importantly, I found correlation that bisexual networks maintain overt boundary disruption, doubly isolated positions oversee “comply and distain” type of response, while lesbian networks anchor boundary integration by affirming “lesbian superiority”. The role of network position in possibly shuffling distinctive belief, perception, and decision underscores the importance of considering larger network dynamics in studying gender and sexuality. Moreover, the large proportion of individuals with bisexual identification without embedded in peer identity network indicate the overlooked possibility of “sexuality without group” and “identity without community”. This paper has broader implications for social movement studies, sociology of gender and sexuality, micro-politics of categories, and the study of boundaries.