That's Talia's new favorite expression and she uses it in context. For example - Chuck (daddy) was in the shower. Talia went in to peek at him. He asked her if she wanted to get into the shower with him.
Talia's reply, "Are you kidding me? Are you seriously kidding me?"
Now that I type it it's not as funny as I thought it was. Here is a picture of Talia, now imagine this little Minnie Mouse voice screaming "ARE YOU KIDDING ME!" all through my house.
Got it now?
Oh never mind I'm going to bed.