Why

I'm not really sure how to type it out, but I'm sure that anyone reading this knows exactly how it sounds, a young kid asks for something, the parent says 'no' and the kids responds with a whiney "wwwhhhhyyyyyy?????" complete with the collapsing body language.
We've all seen it.
As much as I'd love to say that Lily doesn't do this, I can't. She doesn't do it often and we've been working on curbing it, but the real problem now is that Eric does it too! It is kinda funny because he has no idea what why means, she just knows that is what he is supposed to say when he doesn't get his way. It is a tricky thing because I can't use the same techniques to get him to stop doing it.
Another funny thing that he does is if he wants to run around in the store and doesn't want me to carry him he starts saying "ow, ow, ow, ow" so everyonat looks at me like I'm hurting him!