8. Prepare for split personality attack.
Kids are unpredictable and sometimes it’s your own precious angel who decides to go on a rampage when his territory is invaded by other children. Luckily, they usually work things out fairly quickly.

9. The parent trap.
You may encounter parents who bring over a sick kid or extra siblings without letting you know ahead of time. When this happens, speak up if it bothers you. If you don’t, you’ll hold resentment and mistrust and the relationship will never be truly beneficial for you and your kids.