Classic assimilation theory perceives migrant-native intermarriage as both a means to and a result of immigrants’ integration processes into host societies. The literature is increasingly focusing on marital exogamy of immigrants, yet almost nothing is known about their native partners. This explorative study contributes to the literature on migrant integration and social cohesion in Europe by asking whether the native partners in exogamous unions have different attitudes toward gender equality, sexual liberalization, family solidarity, and religiosity/secularization than natives in endogamous unions. Our theoretical considerations are based on preference, social exchange, and modernization theories. We use data of the Generations and Gender Survey (GGS) of seven countries. The sample size is 38,447 natives aged 18 to 85, of whom about 4% are in a mixed union. The regression results of the study are mixed. Persons in exogamous unions show greater agreement with family solidarity, are thus less individualistic than those in endogamous couples. Yet, mixing is associated with greater openness to sexual liberalization and gender equality as well as more secular attitudes. These findings can only partially be explained by sociodemographic control variables. Hence, immigrants in exogamous unions with natives may integrate into the more liberal milieu of their host societies, in which natives continue to place a high value on providing support to family members.