Flavors? Back in my girl guide days in my country there was just one favor the girl scouts did not sell cookies.
Just an excuse for promiscuity. The whole issue is if given a day one decides to marry it would lead to some awkward situations. The lack of commitment in such relationships suits the men better than the women usually since the can separate the physical part better and in the end they can`t possibly end right so its the ending of the friendship as well. Usually in such realtionships the girl does consider herself a sort of girfriend instead of a sparetime hobby as men view it.