My son has played some games at his friend's house (Clash of Clans in particular). As it's a 13 game, he is not able to play it on his tablet as we have blocked it. I need to explain to him why I don't want him to play this and why this isn't ok. I know he will be really upset and say things like "you treat me like a baby" and "everyone else is allowed" (which many are but I don't like this game at all) Any suggestions?