Child support and parenting time are two different issues, and the court will treat them that way. If your ex is behind on child support, they are still entitled to have parenting time with the child if there is a court order or judgment in effect allowing them to. If they are behind on child support, withholding visitation is not the solution. Doing this is essentially taking the law into your own hands and if you do this you may find yourself in hot water with the Court. Two wrongs don’t make a right and as frustrating as your situation might be, it is not the recommended course of action. Child support is enforced by filing a complaint for contempt which is something that should be done sooner than later in order to prevent any arrearages quickly snowballing out of control.