Men's emerging adult romantic relationships forecast downstream relationship behavior, including commitment and quality. Accumulating evidence implicates methylation of the oxytocin-receptor-gene () system in regulating relationship behavior. We tested hypotheses regarding the links between (a) childhood adversity and (b) socioeconomic instability in emerging adulthood on supportive romantic relationships via their associations with methylation. Hypotheses were tested using path analysis with data from 309 participants in the African American Men's Project. Consistent with our hypotheses, results showed that methylation proximally predicted changes in relationship support during a 1.5-year period. Childhood adversity was not directly associated with methylation but, rather, with contemporaneous socioeconomic instability, which in turn predicted elevated methylation. Findings suggest that early adversity is indirectly associated with methylation by links with downstream socioeconomic instability. Findings must be considered provisional, however, because preregistered replications are needed to establish more firmly the relations among these variables.