I'm my own GRANDFATHER!

Surish met Andrew at a bus stop. Surish kept complaining about family problems. Finally, Andrew said, "Listen to my situation. A few years ago I met a young widow with a grown-up daughter, and we got married. Later, my father married my stepdaughter. That made my stepdaughter my stepmother, and my father became my stepson. Also, my wife became mother-in-law of her father-in-law. Then the daughter of my wife, my stepmother, had a son. This boy was my half-brother because he was my father's son, but he was also the son my wife's daughter, which made him my wife's grandson. That made me the grandfather of my half-brother. This was nothing until my wife and I had a son. Now the half-sister of my son, my stepmother, is also the grandmother. This makes my father the brother-in-law of my child, whose stepsister is my father's wife. I'm my stepmother's brother-in-law, my wife is my own child's aunt, my son is my father's nephew, and I'M MY OWN GRANDFATHER!!"