a secret room?? what??

I went to use the restroom tonight and told Mason that I was tired of not having any toilet paper because he kept using it all to make costumes.  (this has been an issue for awhile)  He informed me that he had a lot of toilet paper in his secret room.  Lots and lots of toilet paper and food  ... and toys.  I'm really hoping he isn't talking about his new spot to play, which much to my chagrin in under the stairs.  This needs to be investigated quickly :)