Despite the increase in sexually transmitted infections (STIs) among lesbians, sex education and health services are often heterosexual-focused, leading them to be misinformed about their personal risks. Considering the lack of adequate discussions in offline settings, online spaces allow stigmatized groups to connect, support, and share health information. This study examines how lesbians discuss STIs on Reddit through an analysis guided by the theoretical perspective of the health belief model. A total of 394 posts/comments containing STI-related keywords were observed across six subreddits: r/AskLesbians, r/actuallesbians, r/ActuallyLesbian, r/LesbianActually, r/latebloomerlesbians, and r/lesbian. Results show that users express low perceived susceptibility of STIs and suggest that protection is only necessary when penial intercourse is involved. Despite the belief that protection is effective at preventing STIs, dental dams are not often used due to their inconvenience and testing is an adequate replacement. Perceived barriers to engage in safer sexual practices further complicate users' sexual health decisions. We identify cases where the subreddits serve as cues for action as users actively encouraged others to use protection and get tested. Theoretical and practical implications and directions for future research are discussed.