S.M.
L.,
My 2 1/2 year old does the same thing. He told me he did it to come home because he would rather be at home playing with his lawnmower than at he park. We now take a "manners" blanket (an old receiving blanket) everywhere we go. If I have to speak to him about pushing, hitting, screaming or any other rude behavior he has to go and sit on the "manners blanket". We have a manners song I make him sing with me. It is from "Signing Time" that airs on PBS or you can rent at most libraries. It is totally cheesy but it has worked like a champ. I have only used it once and once he realized he wasn't getting what he wants (to go home) he stopped. I will also in adult situations like while I am speaking with another adult, remind him that I say when we go home not him, and the worse he behaves the longer we will stay. Suddenly he is an angel.
Hope this helps.
S.