Tooth Fairy Nail Polish Magic

I just told Andrew not to touch the nail polish in his sister's bathroom. He then came into my room and said, "Look at my nail polish." Here is what followed:

Me: I told you not to touch it.
Drew: I didn't.
Me: How'd it get on your finger then.
Drew: It was magic.
Me: Now you're lying to me.
Drew: No. It was the tooth fairy.