Research indicates that bisexuals are not only excluded from the heterosexual community, but also become an excluded minority among sexual minority groups (Eliason, 2000) due to their bisexualities cannot be explained by the binary system. They may face the situation of a "double closet" (Lin, 2013; Chen, 2015). Research has also found that the appearance of bisexuals may be interpreted by their partners as a "threat to the relationship" in mixed-orientation couples (Buxton, 2006).
Building on the Sexual Landscape theory (Gordon & Silva, 2015; Rust, 1996), this study aimed to investigate the relational processes experienced by the bisexual-mixed-oriented couples after the bisexual partner coming out in the relationship, focusing on how the emergence of this identity influences couple interactions and impacts both individuals and their relationship as a whole. This qualitative study employed a dyadic design, and used interpretative phenomenology method (Lee & Lai, 2009) for data analysis. Five closed same-sex or different-sex Taiwanese couples (3 same-sex couples including 1 gay and 2 lesbians' partners, 2 opposite sex couples including 2 heterosexual men partnered with female bisexuals) in which one partner identifies as bisexual participated in semi-structured interviews. Data collection has been completed, and data analysis will be completed by spring 2026. The findings of this study will contribute to a better understanding of the cultural structures faced by both partners when bisexual individuals come out within a mix-oriented relationship, as well as the intertwined heteronormative cultures in couple dynamics in Taiwan. We can use understanding to help advocacy efforts and enhance counseling services to better address the unique situations of bisexual-mixed-oriented couples.