Behind her Smile

I smile when I'm happy
I smile when I'm sad
I smile when I'm excited
I smile when I'm mad

At least you think it's a smile
I have upon my face
But that crook in my mouth
Could hide a world of sin

You think that you know me
But you really don't
You only see what I choose to show

So my name is Mona Lisa
And that's all you know
Cause my smile hides everything
I choose for you not to know

So Mona Lisa's smiling
It's true
But am I smiling cause I'm happy
Or am I hiding something from you