She goes into the bathroom, closes the door, sits down on the floor mat in front of the sink, and giggles.
Last night the game had a twist. She would grab Nani's hand and bring her into the bathroom and shut the door, then she would open the door and run out and look around to see if anyone was watching her. Finally I got the message and decided to play along. I snuck over and sat outside the door and when Sadie opened it I said "booo." I heard hysterical laughter as the door slammed shut. Then a tiny crack opened and I saw a tiny eye peering out giggling. After about fifty rounds of this game (quite literally) Sadie was laughing so hard that she couldn't open the door. She would run out and hug me race around and see Daddy and then run back to the bathroom giggling.
I'm not sure why this game is so fun, but Sadie thinks it's absolutely hilarious! The bathroom is her new favorite room in the house! It was not however, conductive to bedtime. It took her a little while to settle down, but then she passed out for the night!