Mesopotamian Wordplay

Tigris:
I have a secret day and nobody knows about it.
Euphrates:
You mean polka dot day?
Tigris:
Hey! and Polka dot night. How come you knew?
Euphrates:
I saw you telling Medina.
Tigris:
I think she's the only other one who knows.
Euphrates:
It's too bad. She's got some Jihad. She's got to wear a veil every day.
Tigris:
It doesn't matter. She can just dream, then. Anyone can dream
anything, even you. I do.
Euphrates:
Truly?
Tigris:
Yes, all the nights are polka dot nights for me.
Euphrates:
I like you Tigris, and your friend Persia, too. It's the way you two say silly things.
Tigris:
And I like you, Euphrates. Your whitefish and your date palms and
your centuries old limes.