I have a friend who is very spoiled and I need help dealing with them.?

I have a family friend, (my mom is friends with his mom) he is the youngest of 3. The oldest and youngest (boys) are VERY spoiled but the middle (girl) child is independent and easy going. I have to say the youngest is far more spoiled than the oldest. For example, Lets say people aren't supposed to eat on the carpet, the mom wont do anything if she sees her kids eating on it but if she sees someone else's kid doing it she will start screaming. Every day that we spend with them its always all about the youngest son and making sure he gets his way. I heard a story about him and how he had hit a kid in the school yard when the school called the mom she began crying saying that he doesn't hit even though Ive seen him jab a shovel into a girls stomach because he didn't want her to walk with us. So basically them mom is blind to her kids wrong doings but critical to other children and parents. I want to be friends with them I just don't know how to deal with them anymore.