From urban dictionary:  Daddy Dom / Little Girl. DDLG, or dd/lg, is a relationship in which one person is the caregiver or "daddy" and the other is childlike. It is NOT a relationship between an actual father and daughter or any minor. This is a type of BDSM relationship that may or may not involve sex, but often involves play with child-like things, such as stuffed animals, bed-time stories, and spankings. The lg part of the relationship is often called the "little."