Finding out that your spouse has been unfaithful is its own kind of awful, and it is completely normal to want the court to know about it. So here is a straight answer, even though it is not the satisfying one. In Missouri, cheating can matter in two specific places, and in both of them it is one consideration among many rather than a thumb on the scale.
Does Cheating Affect Divorce Settlement in Missouri?
Cheating can affect a Missouri divorce settlement in two places, the division of marital property and an award of spousal maintenance, because a spouse’s conduct during the marriage is a factor the statute tells the court to consider in both.
What it does not do is decide the case. It is not a ground for divorce in Missouri, it is not a penalty the court applies, and there is no formula anywhere that converts an affair into a percentage or a dollar figure.
Anyone who tells you what an affair is worth in your case is guessing, and we are not going to do that on a web page.
Is Missouri a No Fault Divorce State?
Yes. Missouri does not require you to prove that anyone did anything wrong in order to get divorced.
Under RSMo 452.305, a court enters a judgment of dissolution once the residency and thirty day requirements are met, once custody, support, maintenance and property have been addressed, and once the court finds “that there remains no reasonable likelihood that the marriage can be preserved and that therefore the marriage is irretrievably broken.”
That is the whole grounds inquiry. No fault appears in it. You can read more about how the process works on our page covering Missouri divorce laws.
This is why so many people are surprised. They expect the affair to be the case, and instead it turns out to be one of several factors in two of the case’s financial questions.
When Does Adultery Actually Become a Legal Issue?
Adultery is named once in the divorce statutes, and it only comes up when one spouse denies that the marriage is over.
RSMo 452.320 covers what happens when the other party denies the marriage is irretrievably broken. In that situation the court has to find one of five specific facts, and the first is “That the respondent has committed adultery and the petitioner finds it intolerable to live with the respondent.”
Two things worth noticing about that.
- It has two halves. The conduct has to have happened, and the person filing has to find it intolerable to live with the other spouse. The statute does not treat the fact of an affair as self executing.
- It is one of five alternatives. Living separate and apart by mutual consent for twelve months, or separate and apart for twenty four months, or abandonment for six months, or behavior such that the petitioner “cannot reasonably be expected to live with the respondent” all get to the same place.
In the ordinary case where both people accept that the marriage is over, none of this comes up at all.
Does Cheating Change How Property Is Divided?
It can, because conduct during the marriage is one of the factors the statute lists, but Missouri does not start from an even split and there is no set adjustment for an affair.
This is where a very common misunderstanding needs clearing up. **Missouri is not a fifty fifty state.** RSMo 452.330 directs the court to divide marital property and marital debts “in such proportions as the court deems just after considering all relevant factors including” five that it names.
Those five are the economic circumstances of each spouse, each spouse’s contribution to acquiring the marital property including as a homemaker, the value of the nonmarital property set apart to each spouse, **”The conduct of the parties during the marriage,”** and the custodial arrangements for minor children.
Two details in that language matter more than the list itself.
- “Such proportions as the court deems just” is not “equal.” Equitable division and equal division are different ideas, and Missouri chose the first one.
- “All relevant factors including” means the list is a floor, not a ceiling. The court is not limited to those five.
So conduct is genuinely in the statute, sitting alongside four other considerations, inside an open ended list, feeding a decision the judge is told to make justly. That is a real place to make an argument. It is not a lever with a number on it. Our page on division of property covers how the rest of it works, and marital versus separate property covers what goes into the pot in the first place.
Does Cheating Affect Spousal Support?
Conduct is one of the factors, but only after the court has already decided that maintenance is available at all, and that first decision has nothing to do with the affair.
RSMo 452.335 works in two stages, and the order is the part people miss.
First, the court has to make two threshold findings about the spouse asking for maintenance. That the spouse lacks sufficient property, including the marital property they were awarded, to provide for reasonable needs. And that the spouse is unable to be self supporting through appropriate employment, or is the custodian of a child whose condition or circumstances make it appropriate that the custodian not be required to seek employment outside the home.
Only if both of those are satisfied does the court move to the amount and the duration, weighing ten listed factors. One of those ten is “The conduct of the parties during the marriage.”
Can You Get More Maintenance Because of an Affair?
Not on its own, and not by any formula, because Missouri has no maintenance calculator.
If the two threshold findings are not met, there is no maintenance award for misconduct to increase. If they are met, conduct is one of ten considerations in a decision the judge makes on discretion.
We are not going to tell you that misconduct “commonly” moves maintenance by some amount, because that number does not exist in any published source. What we will do is look at your actual finances and tell you where the argument is. Our pages on whether maintenance applies and on spousal support generally go deeper.
Does Cheating Affect Child Custody?
Usually not by itself, because custody is decided on what is best for the children rather than on what happened between the adults.
Custody runs on its own statute and its own standard, separate from the property and maintenance questions above. The question a court is answering is about the children’s best interests, and an affair between two adults is not automatically a fact about parenting.
Where it can matter is where the conduct touched the children directly. Who the children were exposed to, whether their routine or their safety was affected, whether a parent’s attention or availability changed. Those are child focused facts, and they get evaluated as such. The affair as a betrayal of a spouse is a different subject from the affair as something that reached a child.
If you are worried about this, it is worth raising specifically rather than generally. Our child custody page covers how these decisions get made.
What Should You Do If Your Spouse Cheated?
Spend your energy on the financial trail rather than on proving the affair, because the money is usually where this actually changes an outcome.
- Look at what was spent. Marital money spent outside the marriage is a financial question the court can consider, and it is often a stronger and cleaner argument than the affair itself. Bank statements and card statements do that work.
- Do not spend ten thousand dollars proving something worth less than that. Investigators and forensic work have their place, and their place is where the money justifies it.
- Write down what you know while it is fresh, including dates and amounts, and hand it to your lawyer rather than to your spouse.
- Keep it off social media. Anything posted becomes evidence, and usually not the helpful kind.
- Be careful about the temptation to make the case about being right. Cases built on being right cost the most and settle the last.
None of that means the affair does not matter. It means the version of it a court can act on is mostly financial.
Who Can Tell You Whether Cheating Matters in Your Case?
The honest answer depends on your finances and your children, and it takes a conversation rather than a web page.
Bardol Law Firm practices only family law, and we are in the Clayton, St. Louis City, St. Charles and Jefferson County courts regularly. If your spouse has been unfaithful, we will tell you plainly where it is likely to matter in your case and where it is not, including when the answer is that it will not move much. That is a more useful starting point than a promise. Our other family law questions and answers cover what comes next.
You are not the first person to sit in this chair, and you are not going to be judged for it here. Every client gets a named paralegal on the file, and we generally return calls within one business day. Call 314.918.0100 or reach us through our contact page. Family Law, Simplified. Fill out the form or call to set up a consultation.
This page is general information about Missouri law and is not legal advice. Every case turns on its own facts. The choice of a lawyer is an important decision and should not be based solely upon advertisements.