Back in the days of dance halls, one would first approach a girl and ask her for a dance, then if that proved successful, perhaps another.
Then came the last waltz, the time to then once again to approach the same girl, it would then generally be during that waltz that one would ask the girl if one could either walk her home, or see her again some time.
It was so easy back then and one made body contact from the very first dance together, not like today when everyone gyrates individually without any close contact being made.