Seriously?

Here is another reason I do not like kids. WTF? We had 6 kids over this weekend for a potluck and this is what I found this morning on the back of my door. Lets say I am less than pleased. These kids are all 3 1/2 and should know better so how did this happen? Harrison has NEVER written on a wall, door, floor... So now I can just add this to my long to-do list. Scrub the door, paint it?? Not happy.