There's no quick answer. If you literally have a 50-50 time-sharing arrangement, then the question boils down to who has greater earnings and income (or the greater earning capacity). Basically, the children are entitled to have the maximum benefit of your combined earnings, no matter where they're sleeping from night to night. So, when he makes more money, he may be paying you support; when you make more money, you may be paying him support. If you want to fight this situation, you'll need to establish why he's unemployed, what his earning capacity is, and whether he's making a good-faith effort to find new employment. if he's sitting around doing nothing, the court may very well "impute" income to him, meaning they will treat him like he's still earning what he previously earned. I recommend that you retain a lawyer for this kind of case. Good luck.