Piano hiding in my garage

I am not sure how else one hides a christmas piano except for in the garage. It's been there for a few weeks with a painting tarp over it. Violet finally inquired as to what "that large item was against the wall, in front of the freezer, where her dad parks" and I told her it was a tread mill for her dad for xmas. I figured that a tread mill still in a box and a box on it's side could be disguised as a piano, so why not. Don't uncover it, I don't want Daddy to find out what it is. Not so sure how to handle "mom, where's the treadmill for dad" but I'm thinking of "oh honey, it didn't work very well so I returned it".