Dean had been outside once they'd gotten things set up, casting a few more Charms around the building to keep it from falling...still. He just wanted to make sure it would still be there. Then there was making sure that they wouldn't be very easily found by those who weren't them.
He heard laughter from inside and made his way toward the door. He peeked inside, arching an eyebrow. "You two are really quite...odd. Are you really going to try out what it's like to jump on people? That sounds painful."