In middle eastern culture it was always the responsibility of the older brother to protect and defend the honor of the family. In the parable of the Prodigal son, the father lost two sons that day- the younger because of his rebellion, the older because of his greed.
Jealousy is always connected to feeling insecure in a relationship, in particular with the level of love and respect. For the older brother this meant he felt like he was a slave and not a son. Perhaps the son wanted the father to initiate the party. He wanted the visible demonstration of love and respect from his father. But ironically even if his father had thrown him a party, it most assuredly would not have been enough. Because love and respect are rooted in the belief of the heart. Very seldom are actions enough. Jealousy places impossible demands.
Perhaps his feeling of inadequacy in his father’s eyes came from his own disrespect. Instead of justifying his actions, he would have done well to have repented for taking the money and not defending the honor of his father. Instead of waiting for his father to allow him to have a party, what kept him from asking his father?