Paris HiltonParis HiltonSomething has made Paris Hilton a Miss Pouty Pants.

Wonder what it could be?

We surmise there could be a couple of things.

Topping the list is that come June 5th she'll be starting her 23 day jail sentence. Not a pleasant thought.

Or maybe she's already thinking of the things she'll miss, like her pooches?

We could keep guessing forever.

Instead, if it's any consolation Paris, you're not alone.

Other celebs have bad days too. Here, have a look at some snaps...