Sibling Rivalry

Just before bedtime last night, Mallory and Preston were playing downstairs. Scott and I were upstairs and suddenly heard Preston screaming. We ran downstairs to find Preston looking like this. We're not sure what happened, but Mallory looked very guilty and Preston kept saying Mallory's name. We assume she pushed him down or into a wall or something, but because they are too little, we couldn't get the whole story from them. They usually play sooooo well together, so I'm not sure where this sibling rivalry came from...but we'll save this picture to show them when they are older:)