Why do you do this?

I love my mom-obviously-but sometimes she drives me crazy. When I'm in a pissy mood or just sort of irritated--not even with her!--she always comes in with this smug, knowing look, and says, "Why are you upset with me? What did I do? You look so angry!"

My response is always through gritted teeth: "I'm fine, Mom."

"You don't look fine, Katie," she says, her expression innocently aggravating. "You look quite upset. What have I done wrong?"

I sort of want to say, everything! Just leave me fucking alone! I'm. Not. ANGRY!

But instead I say, "You haven't done anything wrong, Mom. I'm just in a weird mood. Seriously. You haven't done anything."

She then presses the issue further, going, "No, I obviously have...why don't you want to tell me?"

Maybe because you haven't done anything!! I want to scream, instead saying, at my wit's end, "I'm not mad, Mom, but if you keep going on like this, I will get mad. But at the moment I'm not upset with you."

Then she gets one of those wounded, why-won't-you-tell-me? mother looks on her face, a silently disapproving look etched onto her features, saying, "Fine, then."

Does she want me to be mad? You'd think after the five times I said, 'No, I'm not mad, Mom' she'd get that, hey, I really wasn't mad. How hard is it to understand?

I'm not speaking Martian, am I?