Well, he saw the movie "A Christmas Story", we talked about it, but he still did it!  My 4yr old son decided to try sticking his tongue on frozen metal and learned his lesson the painful way.  I even told him if that ever happened, don't yank it off because all you have to do is pour warm water on it.  Did he listen?  Obviously not!

He screamed, he bled, he cried, he fell asleep with his tongue hanging out.  His big brother felt so bad for him.  He just went out and put a blanket on him a minute ago.  At first he berated him for being so stupid but then he cried because he hates seeing his baby in pain.

I first panicked then of course said "why would you do that?!"  It doesn't seem to make any difference to this kid if I tell him not to do something.  Matter of fact, it seems like he does it quicker if I point out what not to do.  I am terrified of what his teen years will be like!!