This study examined whether relationship involvement and partner gender were associated with between-person differences and within-person fluctuation in positive and negative affect and alcohol use among people who are attracted to more than one gender or regardless of gender (e.g., bisexual, pansexual, queer; bi+). One hundred and ninety-eight bi+ individuals (M age 26.97; 73.1% non-Latinx White) completed a 28-day diary study. Multilevel regression analyses modeled between-person differences in daily affect and alcohol use as a function of relationship status and partner gender. ANCOVAs were conducted to examine differences in within-person fluctuation. Results partially support past findings that relationship involvement may not confer benefits for bi+ people and that mixed-gender partnerships could be particularly challenging. Future research directions are discussed.