Give them enough responsibilities. Set realistic in its philosophy. Never laugh of their jokes.
No chimney no adventure or break the routine and is always in a bad-mood.
When paint AQUELE adventure, say, bored with air - "I am not so ..."
Do not accept any kind of dispute or game.
Repeat always - "It is time?"
Do everything you can to prevent that trip from his vacation. Make insinuations about culture little of his parents or other relatives.