in the book The Power of Six by Pittacus Lore, Sam, john and number six are on the run from the FBI after being wrongly accused of killing 5 people.  they find a nice spot to settle down and train for a little bit.  meanwhile sam grows fond of number six.  after a few days so does john.  john, since not human, can fight and has many more skills than sam who is a small human.  this and the fact that  he thinks john has a better chance with six makes him jealous of john.


          i think sam is jealous of john because one time when they were training six brought john to the ground and they stared into each other's eyes for a couple seconds.  meanwhile sam got angry and walked back into the house.  when john came into the house sam told him angrily that he liked her first and that he was being greedy because was already dating "the hottest girl in Ohio."


          in conclusion sam was jealous of john because sam liked six and he thought john was being greedy.  sam was a small nerdy kid and john was a muscular and athletic man.  that is how sam viewed     the two of them and based on that the odds are not in his favor.