Who is my Grandfather?

 

 

I met a widow, who lived with her step-daughter. I married her. My father fell in love with the step daughter of my wife, and married her. My wife became the mother-in-law of my own father: my wife’s step-daughter is my step-mother. My step-mother, who is the step-daughter of my wife, has a boy: he is my step-brother because he is the son of my father and of my step-mother; but as he is the son of my wife’s step-daughter, so is my wife the grandmother of the boy, and I am the grandfather of my step-brother. My wife also has a boy, my step-mother is consequently his step-sister and is also his grand-mother because he is the child of her step-son; and my father is the brother-in-law of my son. My son is the grandson of my father.

Who is my grandfather?