If there is a court order requiring that your exspouse pay variable costs and those variable costs remain unpaid (in my opinion for more than 30 days) unless your judgment of divorce or temporary order identifies a different timeline, you may file a contempt motion at any time. You may want to advise your ex that if the payments are not paid timely it is your intent to bring the motion.
Just one additional point to my colleague's excellent reply - you'd asked if you'd be required to pay support.
Either one of you can request a modification of a support order if there has been a substantial change in circumstances. For example, if you got a huge raise, or got laid off, that would be considered a substantial change of circumstances. If it's been three years since the original order was made, that is by law "substantial change of circumstances" that would allow either party to request a modification.
There's not enough information in your question to say for certain, but it sounds like neither of you pay child support to the other now. Unless there has been a substantial change of circumstances, there would not be a basis upon which that the court would modify those standing orders.
You may want to consult with an attorney to work through the math on child support. Wisconsin has a default statutory formula for calculating child support that is based on the number of children, time spent with each parent and the gross income of the parents. If your income is substantially higher than your husband's and that wasn't the case when the child support order was made, you may want to evaluate the risk of kicking a hornet's nest before you charge in with a contempt motion. Please take the time to review the situation with your attorney.
1. This reply is for educational purposes only and is not legal advice.
2. No attorney-client relationship has been created by this reply.
3. If you need legal advice, consult a licensed attorney in your
state to make sure you understand both your state and
federal laws concerning your issue. Your attorney will need
specific and complete facts to provide you with legal advice.