Hi my 19 month is throwing things at people and finding it absolutely hilarious. Even when I say no don't do that he just bursts out laughing? We've started to go to some baby groups and he's doing it there too and I'm really worried he's going to his another child. Any advice on how to get him out of this habit? He's such a lovely boy I don't want him getting the reputation as 'that naughty kid'.