Unfortunately, if he has no independent source of income (i.e., a job), then getting him to pay what he owes will be next to impossible. The court isn't going to take his parents' money - they don't owe you a dime. The fact that he is living off of them isn't something the court can do anything about - they can tell him that he has to pay you, but without some source of money that the court can latch onto - a paycheck, independently-owned assets, etc., then all the orders in the world aren't going to matter. You cannot MAKE someone hold up their end of the bargain unless you have a way to ENFORCE the order. Unemployment could be garnished to some extent, but if your alimony amount is substantial, then you simply aren't going to get paid what you're owed. And, it's up to you to chase after him - the court isn't going to do it for you.
This answer is not to be considered a response to a specific legal issue in a specific jurisdiction - it is to be considered only a general response to a hypothetical scenario posed by the questioner. For specific legal advice, please consult with a licensed attorney in your jurisdiction.
Court orders can be modified based on a material change in circumstances. This means that you could have filed a motion to increase alimony when you were injured and disabled.
He will remain obligated to pay the current order until he files a motion to modify. If he doesn't actually pay, an arrearage will accrue until he obtains a modification.
If he is no longer employed, his obligation may be reduced, but he will probably still be ordered to paying something, especially if he is receiving unemployment.
You have the right to bring him to court by filing a contempt citation. That will, of course, give him an incentive to file the motion to modify and get the amount reduced. However, if the alternative is, as you put it, not eating, then it is obvious that you need to file the contempt.
A lawyer would help you get the best possible result. If he is found in contempt, the court may order that he pay some or all of your legal fees and the costs of the motion.
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