All of these young ladies seem to be showing their appreciation. The lesson is going very well judging by the reactions.
The young lady below has a perfect expression. No pat, pat, rub, rub here. She knows she is going nowhere and that you are completely in charge. She looks ecstatic and may need a little extra help when you have finished her spanking to bring her to full ecstasy. When she reaches full ecstasy, I suspect her face will look exactly the same. The moment when pain and pleasure are indistinguishable.