Why did more than even one SENTENCE of this happen in front of your son? That's simply UNACCEPTABLE, and you BOTH have the responsibility for protecting him. You should have cut off the conversation right there, and said "If you'd like to discuss it in private with me, I'd be happy to, but this is not a topic we should be discussing in front of our son," -- AND ENDED IT.
btw, he's clueless about "working at McDonald's" thing. A judge can IMPUTE A REASONABLE INCOME to him, based on what he's qualified to do and what jobs are available in your area. A parent can't just intentionally "under-employ" themselves, to avoid paying either child or marital support.
