You can sue your husband’s mistress for alienation of affection only if you live in one of the few states that still recognize the claim, and only if you can prove she was a substantial cause of your marriage’s breakdown while you were still together. As of 2026, that short list includes North Carolina, Mississippi, South Dakota, and Hawaii, with Illinois sometimes cited although claims are rarely pursued there. If you are anywhere else, this lawsuit is not available to you.
Two states came off the list recently. New Mexico’s Supreme Court abolished alienation of affection in January 2026, ending a rule that had stood since 1923. Utah’s legislature also eliminated it, enacting language that there is no right of action for alienation of affections. Older articles and directories still list both states, so double-check any source that predates 2026 before you rely on it.
What You Have to Prove
Alienation of affection is a civil claim against a third party who interfered with your marriage and caused your spouse’s love to fade. You have to establish three things:
- Genuine love and affection existed in your marriage before she came into the picture.
- That love was destroyed or significantly diminished.
- Her conduct was a substantial cause of the loss.
The third element decides most cases. Proving she slept with your husband is not enough on its own. You have to connect what she did to the actual collapse of affection in your marriage. That is why these cases lean so heavily on before-and-after evidence: text messages, emails, social media activity, financial records showing gifts or shared expenses, and testimony from friends or family who saw the marriage change after she entered it. Some plaintiffs use private investigators. Expect the discovery process to be invasive for everyone involved, including you.
Criminal Conversation: The Companion Claim
In states that recognize it, criminal conversation is a separate civil claim focused only on whether the third party had sexual intercourse with your spouse during the marriage. The name is misleading. It is not a criminal charge, and you do not have to prove your marriage suffered or that any affection was lost. The only question is whether the sexual relationship happened while you were legally married.1Legal Information Institute. Criminal Conversation Tort
Not every state that allows alienation of affection also allows criminal conversation. Where both exist, plaintiffs usually file them together because the evidence overlaps. Proof of the affair supports the criminal conversation claim directly and helps establish the interference needed for alienation of affection.
How Long You Have to File
Every state that permits these claims imposes a filing deadline, and the clock does not always start when you think.
North Carolina gives you three years from the last act of the defendant that gave rise to the claim. If the affair ran over a long stretch, the clock runs from the most recent conduct, not from when it started or when you found out. North Carolina also cuts off any conduct that occurred after you and your husband physically separated with the intent that the separation be permanent. Anything she did after that separation cannot support your lawsuit.
South Dakota applies a six-year statute of limitations for criminal conversation. Other states set their own deadlines, and some fall back on general personal injury limits rather than a specific heartbalm rule. Check your state’s deadline early. These cases take months to build, and the filing window can close while you are still gathering evidence.
What You Could Recover
Damages fall into three categories, though how much you might actually see depends on the jurisdiction and the facts.
Compensatory damages cover the actual harm: loss of your husband’s love, companionship, affection, and support, along with mental anguish, humiliation, and any injury to your health or reputation. Punitive damages become available when her conduct was willful, malicious, or showed reckless disregard for your rights. Evidence of a sexual relationship often supplies the aggravating factor a jury needs to award punitives, and those awards can exceed the compensatory amount by a wide margin. Nominal damages are a token sum a court can award when a legal wrong occurred but you cannot quantify your losses.
Verdicts are unpredictable. Juries have returned everything from a few thousand dollars to millions, and appellate courts sometimes trim large awards. The emotional weight of the evidence cuts both ways: a sympathetic jury may reward you generously, but a skeptical one may focus on whatever problems your marriage already had.
Defenses She Will Raise
Her lawyer has a familiar playbook, and some of the defenses work well.
The strongest is that your marriage was already failing before she arrived. Prior separations, existing affairs by either spouse, or documented conflict all undercut the claim that she caused the loss of affection. Courts ask whether her conduct was the substantial cause of the breakdown, not just one factor among several. A marriage already in serious trouble is hard to alienate.
Consent is another defense. If you knew about and approved of the affair, encouraged it, or were in an open marriage arrangement, she can argue you cannot now claim injury from conduct you permitted. A related concept, connivance, applies if you actively engineered the affair to use it later as leverage in divorce.
She may also argue she did not know your husband was married. That is not always a complete defense, but it can reduce damages, especially punitives, which require willful or malicious conduct.
And she will raise the statute of limitations if there is any opening. In North Carolina, the rule that only pre-separation conduct counts gives defendants a hard cutoff to argue.
What This Will Cost You
These lawsuits are expensive, slow, and emotionally punishing. Weigh that honestly before filing.
Court filing fees for a civil tort complaint generally run from about $200 to $450 depending on the jurisdiction, and that is the cheapest part. Attorney fees for a case with extensive discovery, depositions, and a possible jury trial can climb into tens of thousands of dollars. Some attorneys in North Carolina, where larger verdicts are more common, will take these cases on contingency. Many require hourly payment.
Then there is your privacy. Every detail of your marriage, the affair, and your own behavior will be examined in depositions and possibly at trial. The defense has every incentive to portray your marriage as dysfunctional and you as partly responsible for its failure. If you have children, the public nature of the case can affect custody dynamics and expose them to painful information.
Collection is a separate problem. Winning a judgment and actually collecting money are not the same thing. If she has no significant assets or income, even a large verdict may be uncollectible, and you can spend years in litigation holding a piece of paper worth less than the fees you paid to get it.
How It Interacts With Your Divorce
A lawsuit against the mistress is a separate legal action from your divorce, but the two run in parallel and affect each other. Discovery in one case can surface in the other. If you are pursuing alimony or a favorable property division, airing the affair through a separate lawsuit can sometimes strengthen your negotiating position, though it can also make settlement harder if the other side feels cornered.
Any damages you recover from her are separate from your divorce settlement or alimony. A verdict against her does not reduce what your husband owes you. But running two lawsuits at once multiplies your legal costs, and some judges grow impatient with a litigant who appears to be using the heartbalm case as a tactical weapon in the divorce rather than as a genuine damages claim.
For some plaintiffs, the accountability matters as much as the money, and a verdict delivers something a divorce alone does not. For others, the price in time, privacy, and legal fees turns out to be higher than the outcome is worth. Going in with clear eyes about both sides is what separates a strategic decision from an expensive one made in anger.