the small of her back (thing)

In dancing school I was told to place my hands there,
later I was told not to touch anywhere, there (unless)
they wanted me to, which some did, some times.

It is a soft smooth place and fits my hands well (usually)
it is both a place to lead and a place to be lead to
but it is not the smallest place on her body,
it is a large area, compared to the nape of her neck,
or the inside of her wrist (where she puts perfume)
still,

this is the small where it started for me, and often
where it ends- as well.