Any one know the answer to this riddle?

[thatoneguy1]

Two men are walking in a graveyard. The first man walks to a grave.

The second man says, "Who is in that grave?"

The first man points to the grave and says, "Brothers and Sisters I have none, But that man's father, is my father's son."

*Who is in the grave?*

I can't find the answer for it and it's driving me crazy!

 

[Krissy]

It's the first man's son. "My father's son" is referring to him since he has no brothers or sisters. So, "That man's father (aka him) is my father's son" means the first man's son. I had to draw a picture to figure it out XD