Project Summary/Abstract This study is guided by a long-term goal of optimizing alcohol-related intimate partner violence (IPV; psychological, physical, sexual, and identity abuse [e.g., threatening to out a partner]) interventions for bisexual and other multigender-attracted (bi+) young adults and their partners. As a critical first step toward this goal, this R21 will identify modifiable intervention targets for alcohol-related IPV by developing new scientific knowledge of the unique day-to-day processes that potentiate and ameliorate IPV after alcohol use among bi+ young adults and their partners. This study will also explore subpopulations of bi+ young adult couples who should be prioritized in future alcohol-related IPV research (e.g., same- vs. different-gender dyads). Alcohol use proximally increases the likelihood of IPV perpetration, particularly among young adults ages 18-25. Relative to those with other sexual identities, more bi+ young adults endorse heavy alcohol use and IPV, but research has not identified daily experiences that may potentiate or mitigate alcohol-related IPV within this priority population. This critical scientific gap may be attributed to (1) limited inclusion of bi+ populations in alcohol-related IPV research, with no daily diary studies focusing on bi+ young adults, (2) a lack of data on bi+- specific minority stressors in existing alcohol-related IPV research, and (3) limited couple-level data from bi+ young adults despite IPV being a dyadic process impacted by both partners’ alcohol use and minority stress. This study will address these gaps by examining potential intervention targets (i.e., bi+ minority stress, partner support) implicated by sexual minority alcohol-related IPV theory that exacerbate or mitigate IPV after drinking in the naturalistic settings of bi+ young adults and their partners. A rigorous, 60-day, daily diary approach will be used to collect daily reports of alcohol use, minority stress (e.g., bi+-specific stressors), partner support, and IPV perpetration/victimization from 50 bi+ young adults and their partners (N=100 individuals; 25 same-gender couples, 25 different-gender couples). Study aims are: (1) Determine if one’s own and one’s partner’s alcohol use increases IPV perpetration on days when bi+ individuals and their partners report high, but not low, levels of minority stress. (2) Determine if one’s own and one’s partner’s alcohol use increases IPV perpetration on days when individuals perceive their partners as providing low, rather than high, levels of partner support. (3) Across Aims 1 and 2, explore descriptive differences between (a) same- and different-gender dyads, (b) couples in which only one partner has, rather than both partners having, a minoritized sexual identity, and (c) IPV types to identify priority populations for future research. Data generated from this study will provide the most comprehensive, theoretically-informed assessment of alcohol-related IPV among bi+ yo...