I must strip naked and kneel on a chair to be caned... by step mother

When my step mother is fed up with my behavior ... and between you and me, it doesn't seem to take very much...
she tells me to strip naked, and get in position.
I soon learned, this means, kneel on the seat of a chair, and bend my waist over the back of the chair.
If my step-sisters are home, they are allowed to watch.
She uses rope to tie my wrists to the back supports.
She gets out her senior cane, and beats my bottom to a very bright red, with ugly welts across it.
I am always sobbing, halfway through the punishment.

When she is done, she walks away to put up the cane, and leaves me there, for my step-sisters' viewing pleasure, until such time as she thinks it's been long enough.
She invariably threatens to let my step-sisters deliver some cane strokes, but it hasn't happened...yet.