There is a group of young men who went on a trip to one city. One of them was in charge of booking tickets for the whole group of 19 people, and three of them agreed to set him up without the others knowing anything about it. Their plan was that one of the three would accuse the leader and his assistant of not booking a ticket for him despite the fact that he was with them in the airport. The argument between them became very heated and made the others worry that there would be a fight before they traveled. After five minutes the three youths put matters straight and told them all that what they had done was just a joke. Our question is: is the trick that they played and which could have led to the group not trusting the leader and his deputy permissible?