What is my father-in-law is my wife?

's father.

Your father-in-law is a person who is related to you through marriage. He is the father of your spouse (your wife in this case). He may have additional roles in your family, such as being a grandfather to your children. Your relationship with your father-in-law can be an important one, as he may provide advice, support, and guidance as you navigate married life and family dynamics. It is important to show respect and appreciation for your father-in-law, as he is an important member of your spouse's family and your extended family.