My two year old son has been pushing my one year old nephew down on purpose. He doesn't actually hurt him, but what is the best way to explain to him that it's bad for him to push down his cousin? This is a first for me, because he normally gets along with his older cousins.
Your 2-year-old isn't actually safe to be with his younger cousins just yet -- without adult supervision. He can't help himself -- even though he doesn't mean to hurt the little guy, he is bound to act out, push, and grab. Your son needs you to stay close by to help him play nicely with his cousin. Don't scold, but talk him through how to play and have fun with other children. 2-year-olds need to know where the limits are -- that's they're job, to push the limits to find out where they are. It's our job as parents to gently show them the limits -- which will help him learn self-control as he gets older.