how do you involuntarily move and react while being spanked

When the spanking is slow and hard, do your feet do a little dance like this. Mine sometimes do.
If it is still early in the spanking, the spanker might like to see you react, and wait until your movement subsides, and then deliver another strong spank
However, more rapid hard spanks can really cause the spankee to start to lose control
 which to me is the goal of the spanking
the goal to make the spankee really have no other thoughts than the intensity of the pain and the wishing for it to stop.
A stoic spanking to me is not effective.

Bouncing around trying desperately to avoid the spanks that cannot be avoided
or at least reacting to a slow steady, unending spanking
will definitely be one that you remember
Love the feet moving upward by Audrey. My last caning had the same reaction of the feet rising upwards, much to Cindy's surprise.
 A real spanking certainly makes the body react
Crossing your feet, somehow, in your subconscious does not help
Hope you enjoyed the gifs.

Maybe you might like to comment on one that is similar to your reaction while being spanked?

bottoms up



Red