Up to No Good, but Doing it Together

Cougar had no school yesterday and he and Juliet were getting along much better than usual. They drug their blankets and toys into the bathroom (yuck!) and built a fort. The next thing I know, the sink is full of water and together they are bathing their favorite stuffed animals.
How can I get mad at that? They were up to no good, but they were doing it together. I just closed the door and kept on going and decided I was going to be grateful that they were bonding as brother and sister, darn the wet stuffed animals.