Question
 

My young stepmom notify she will spank me sometimes it will be necessary? How should I answer this?

It Depends!
 

It depends on whether you have ever been spanked by a woman before and whether you are really curious as to how she will do it and what she will hit you with.

You could just say something like "I am too old to be spanked" or "you wouldn't dare" and see how far she will go.

Interesting situation
 

You seem to make a point of your stepmother's age. Is this a concern for you. Why are you being punished? I also sense an interest on your part. Have you been spanked before? Has this been brought to your father's attention? Perhaps you would prefer for him to administer the spanking and it would be interesting to know if he spanks your YOUNG step mom.