Nearly half of adults in the U.S. indicated they had a close step-relative that included stepparents, stepchildren, and other close relationships. The prevalence of stepfamilies is rapidly increasing and represents a population that remains largely understudied. This study explored the roles of socioemotional behaviors (positivity, negativity, and sexual interest) on marital stability for different remarriage constellations (depending on which of the couple, both partners, or neither had previous children). This study uses dyadic relationship data from 879 couples. It was hypothesized that positivity and sexual interest would be inversely related to marital instability, while negativity will be correlated with marital instability.