Having children comes with the obligation to support them. That is an obligation most mature adults realize that continues regardless of whether or not a marriage continues. For some narcissistic ex-spouses, however, there may be major resentments about having to pay child support and, as a result, stubborn non-compliance with court orders. This can lead to the necessity of wage garnishment orders, seizure of funds from bank accounts and even incarceration for contempt of court.
The problem is that for a narcissist, everything is about them: their needs, their wants, their desires and their money. But, narcissism is not just a pejorative label - it is an actual personality or mental disorder. Those suffering from it have an inflated sense of their own importance and their superiority over others. They disregard other people's feelings and needs, and believe that they should be admired. A lot of that, of course, is on the surface, and they often greatly fear any criticism.
To appear successful and superior to the world - at least in their own eyes - they may live beyond their income, having little left for their true obligations, like the child support that they may resent having to pay. They may have absolutely no guilt about shortchanging people with less power, including their own children.
Not all non-custodial parents fall into this category, of course. It is a distinct minority. But, one can suspect that many custodial parents recognize their ex-spouse in this description. The majority of non-custodial parents do honor their obligations to their children and would never be non-compliant with a court order. Exceptions occur in instances of objective difficulty, such as a job loss, major illness or injury or a cutback in their pay or hours. In such circumstances, the best course will be to consult with an attorney to see if it is time to go to court to seek a modification of a child support order based on those changed circumstances.
Source: Huffington Post, "Who's Not Honoring Me Now? How Your Narcissistic Ex Really Feels About Child Support" Christina Pesoli, Jan. 23, 2014