Sometime, water of a different density flowed around the princess.

Streaming down the side of her face, until they died out and she returned to the surface...

They're called "tears", but don't tell her.

Okaaay!

About the man who didn't come back that day.

He worked hard, and made a family for himself.

He grew old, and passed away happily surrounded by his grandchildren.

The grandson who went to check out his gramp's mermaid story told the princess so.