I enjoyed this but, then, I'm partial to a long slow build of suffering. I like to get my sub off with a vibe in such a predicament as this while whipping her. Eventually, I take away the vibe, and she discovers she's still reaching orgasm from just the whip. When she realizes what has happened, there is an interesting transformation in the way she thinks of herself.
How is this "punishment"? Take a leather strap to her tits and teach her what punishment is all about. She was crying at the end?? Really!? Give me 30 seconds with her and I will have her crying for real!