The quick answer is “maybe” with respect to alimony (which we now call maintenance), and “yes” with regard to child support.
As to alimony/maintenance, Illinois law states that maintenance will terminate if your ex-wife cohabits with another person. There are many cases explaining what this means. In short, it has to be something more than a sexual relationship. They have to spend time together, act as husband and wife, and share things such as social events and possibly even finances.
A court motion to terminate alimony/maintenance should be filed. If this sort of a relationship can be proven in court, then her support will be terminated as of the date that the relationship started.
As to child support, there is no law that would terminate the support payments for your child. There are other issues, however, to be considered. It might not be good for your children to be living with your ex-wife’s boyfriend. He might be a low life, or the children may not get along with him. Maybe, he even mistreats them.
If these things, or something similar, are happening, you might be able to change the custody or parenting time provisions in the dissolution judgment. Illinois law allows for modification of your dissolution judgment if the court finds that there has been a recent change effecting the children and modification is in their best interests.
Again, a court petition is necessary. You would have to show that moving in with the boyfriend is a change which effects the children and that it would be in the best interests of your children to modify the current arrangements. If you have sufficient evidence, then the court could make modifications to your dissolution judgment. In fact, if custody was transferred to you, your child support would likely end. Possibly, your ex-wife would even end up paying you child support.
Jay A. Frank is a senior divorce practitioner with Aronberg Goldgehn Davis & Garmisa in Chicago. He has been selected as one of the top family-law attorneys in Illinois. With more than 35 years of experience, he focuses his practice on all aspects of Illinois family law. He can be reached at (312) 828-9600. View his Divorce Magazine profile.