Try To Figure This One Out

I Am My Own Grandpa Many, many years ago When I was twenty-three I got married to a widow Pretty as could be. This widow had a grow-up daughter With flowing hair of red. My father fell in love with her, And soon the two were wed. This made my dad my son-in-law And changed my very life. Now my daughter was my mother, For she was my father's wife. To complicate the matters worse, Although it brought me joy, I soon became the father Of a bouncing baby boy. My little baby then became A brother-in-law to dad. And so became my uncle, Though it made me very sad. For if he was my uncle, Then that also made him brother To the widow's grown-up daughter Who, of course, was my step-mother. Father's wife then had a son Who kept them on the run. And he became my grandson, For he was my daughter's son. My wife is now my mother's mother And it makes me blue. Because, although she is my wife, She's my grandma, too. If my wife is my grandmother, Then I am her grandchild. And every time I think of it, It simply drives me wild. For now I have become The strangest case you ever saw, As the husband of my grandmother, I am my own grandpa!