Affinal relationships are those created through marriage rather than blood, like a stepparent or an aunt or uncle who marries into the family.
Affinal relationships play an important role in family dynamics. These connections are made through marriage, like when someone becomes your stepparent, or when an aunt or uncle joins the family by marrying your blood relative. The term comes from the Latin word affinis, meaning "connected by marriage." Even though they aren’t related by blood, affinal family members can be just as close and important as your other relatives, adding to the richness and diversity of your family.