Help me sort out who is whose child...

An old man had an affair with his eldest daughter-in-law.
After the discovery, the eldest son divorced her.
The daughter-in-law became a stepmother.
The old man married the eldest daughter-in-law.
The eldest son said his child didn't look like him.
Suspected the child was the old man's.
A paternity test confirmed it wasn't his.
But it also wasn't the old man's.
It was the second son of the old man.
The eldest son, furious, fought with the second son.
And claimed that the second son's child was his own.
The second son took his child for testing, and it turned out to be the eldest son's.
But the eldest son has an Oedipus complex.
The second son is actually the son of the eldest son and his own mother.
Now the family is still living together.
The eldest daughter-in-law takes care of the old man and the eldest son.
The second daughter-in-law takes care of the eldest and second sons.
The eldest and second sons swapped children.
额😂