Introduction. Sexual fluidity refers to one or more changes in an individual’s sexual orientation dimensions (identity, attractions, sex/gender of sexual partners). As more researchers and clinicians begin to examine sexual fluidity in adolescents and young adults (AYA), it is necessary to understand how youth themselves think about sexual fluidity.

Methods. Qualitative data were analyzed from the Sexual Orientation Fluidity in Youth Study, which recruited AYA ages 14-25 years in the US from an online survey panel. Participants were asked an open-ended question about how they understand sexual fluidity : “What does it mean for a person to be sexually fluid?” (with the option to write “I don’t know”). An inductive thematic analysis was conducted on responses from a random sample of participants (roughly 10% of total sample: N=368) stratified by past change in sexual orientation identity (yes, no) and age (ages 14-17, 18-21, 22-25 years).

Results. AYA shared particular levels of understanding and ways of conceptualizing sexual fluidity, which fell into three main themes: 1) Sexual fluidity as change(s) in attraction (e.g., “I would assume it means their attraction changes over time and isn’t fixed as one label”); 2) Sexual fluidity as changes in sexual orientation identity (e.g., “They could have multiple ways to identify their sexuality and it could change from time to time”); 3) Sexual fluidity as having varied sexual behaviors or interests (e.g., “to be interested in a lot of things sexually”). Beyond the three themes, 25% of the sub-sample reported not knowing what it means to be sexually fluid.

Conclusions. AYA can identify complexities in sexual orientation and fluidity, describing the three dimensions of sexual orientation. The varying ways in which AYA understand the complexities of sexual orientation change beyond identity highlight the need for researchers and clinicians to broaden how they measure and discuss changes in sexual orientation. Understanding youth perspectives on sexual fluidity can improve sexual fluidity measurement in research and foster more inclusive and affirming health environments.