I'm my own grandpa

When i was 23, i got married to a WIDOW, she had a grown up DAUGHTER, and my FATHER fell in love with the daughter. This made my father my SON-INLAW. my daughter was my MOTHER because she was my father's WIFE. then i had my own SON, who became my father's GRANDSON & BROTHER-INLAW, and also my UNCLE. if he were my uncle, that made him the BROTHER of the widow's grown up daughter who was my STEPMOTHER. my father's wife had a son, he became my GRANDCHILD because he was my daughter's son, my wife is now my MOTHER'S MOTHER. if my wife is my GRANDMOTHER, then i'm her GRANDCHILD. then as the husband of my grandmother, that makes me my own GRANDFATHER.