Spartans ( IN their wisdom) had a period which lasted a couple of hundred years during which , upon reaching a certain age ( I believe it was 16) they coupled the men/boys with women who were at least twice their age, and coupled young women with men who were at least twice their age… these relationships were not supposed to turn into marriages ( although some did) but they were a way for the young to get experience and learn about the opposite sex…. I always liked the idea