I Am My Own Grandfather

The family tree has gotten a lot more complicated on Once Upon a Time with the most recent reveal that Peter Pan is Rumpelstiltskin's father.

This boy

is the father of this man

who has a son named Baelfire

who has a son named Henry.

That's the easy part of the family tree. This is where it gets  more complicated. Henry's mother is Emma.

Who is the daughter of Snow White and Prince Charming.

Snow's step- mother is the Evil Queen Regina

Who is also the step-mother of Henry

Which makes Snow White Henry's step-sister, but also his grandmother.

To top it off, the Evil Queen Regina's mother is the Queen of Hearts. 

When the Queen of Hearts was younger, she was also the millers daughter that needed Rumpelstiltskin's help to turn straw into gold. They were also involved with each other.

Rumpelstiltskin first wife ran off with Captain Hook.

When Baelfire was a child he was abandoned by Rumpelstiltskin and was temporarily adopted by the Darlings.

To protect the Darlings, Baelfire went to Neverland where he and Hook and a brief companionship (until he found out about his mother)

Now Hook and Baelfire are both competing for the love of Emma.

This means Hook was with Henry's grandmother and his mother.

There are different reasons why some of the characters don't age while others do, and there is a lot of world jumping which adds to the complications to the relationships. The creators quiet enjoy making everything connected.