My friend wants me to buy him a new ball, do you think I'm a jerk if I don't buy him one?
What is the reason you won't buy him a ball?
He won't ever kick the ball when I play with him.
That isn't a nice thing to do. You should do what you can to help out a friend. Maybe you can teach him what to do with the ball when you want to play together.
Maybe I'll just buy a ball and not let him play with it. That'd be funny!
Are you sure that your friend would think that this is funny? I'd hate to see you ruin your friendship over something like a silly ball. Maybe you and your friend should just stop playing ball together.