What's it mean when some asks are you an innie or outie?

It's like, 'do you sleep in a house or a backyard?'. It's actually very rude.

Belly button

I don't know as I have never been asked this question.

It usually means belly button, but sometimes they could be asking if you are male or female.

Navel. It's whether or not your navel is an innie or an outie.

ur belly button - a friend of mine said his wife had an innie but when she had her 2nd child her belly button became an outtie - my friend said it felt like the inside of a dogs ear lol he never told her that! :)

Belly button

belly button or labias

Your navel, does it stick out or is it a depression?

your navel.

is it icky outty or a mini inny. :P