In a handful of states you can sue someone for sleeping with your spouse, using civil claims called alienation of affection and criminal conversation. Roughly six states still allow these lawsuits: Hawaii, Mississippi, New Mexico, North Carolina, South Dakota, and Utah. Everywhere else, the affair partner is legally out of reach, though the adultery itself may still affect your divorce.
Where the Lawsuit Is Available
Most states abolished these claims decades ago through what are commonly called “heart balm” statutes. Illinois was among the last, eliminating them in 2016. North Carolina is the most active jurisdiction today and produces nearly all the headline verdicts. Criminal conversation survives in even fewer states than alienation of affection.
The law of the state where the interference happened controls. If you don’t live in one of the six states, you cannot bring either claim, and you generally cannot file in a state that recognizes the claim if the conduct occurred somewhere that doesn’t. There is no federal version of these torts.
The Two Claims You Can Bring
These are separate torts, and where both are available, plaintiffs often file them together. They target different wrongs and demand different proof.
Alienation of Affection
Alienation of affection is a civil claim against a third party who interfered with your marriage and destroyed the love between you and your spouse. The focus is the interference, not the sex. You don’t have to prove a physical relationship at all.
To win, you generally need to show three things: that genuine love existed in the marriage before the interference, that the love was destroyed or diminished, and that the third party’s actions were the controlling cause of that loss. The third party doesn’t need to have intended to wreck your marriage specifically. It’s enough that they acted in a way that would foreseeably damage the marital relationship.
In theory a parent, counselor, or friend could be a defendant if their conduct broke the marital bond. In practice these cases almost always target a romantic rival.
Criminal Conversation
Despite the name, this is a civil claim, not a criminal charge. It is narrower and more straightforward than alienation of affection: you sue the third party for having sexual intercourse with your spouse during the marriage. A valid marriage existed, the defendant had sex with your spouse while it was intact, and that’s it. Even a single act of intercourse is enough.
You don’t have to prove emotional harm or that the affair damaged the marriage. The sexual act itself is the wrong. The trade-off is that you need concrete evidence that intercourse actually occurred, not just that your spouse and the third party were romantically involved.
The Evidence You’d Need
Both claims use a preponderance of the evidence standard: more likely than not. That’s a lower bar than a criminal case, but it still requires credible, organized proof.
For alienation of affection, the hardest piece is showing real love existed before the third party appeared and that their conduct destroyed it. Testimony from friends, family, neighbors, or coworkers who saw the marriage before and after is often essential. Wedding photos and anniversary cards don’t prove a happy marriage on their own, but they support a narrative other witnesses can corroborate. Communications between the third party and your spouse carry significant weight: text messages, emails, social media messages, and call logs that show the nature and timeline of the relationship. Evidence that the third party pursued your spouse aggressively, sent gifts, or made plans to be together strengthens the causation argument.
Criminal conversation demands proof that intercourse actually happened. Photographs or video showing the third party and your spouse entering a hotel together and staying overnight can establish what courts call “opportunity and inclination.” Explicit messages discussing sexual encounters are often the most direct proof available. Private investigators are commonly hired to document physical affection, establish that the parties had the chance to be alone behind closed doors, and preserve communications. Investigators typically charge $100 to $200 per hour, and weeks of surveillance can add up fast.
Defenses the Affair Partner Will Raise
Defendants have several avenues to fight back, and some work well.
The most common defense to alienation of affection is that the marriage was already dead. If the couple slept in separate rooms, fought constantly, or had already talked about divorce before the defendant appeared, the defendant can argue they didn’t cause the breakdown. This attacks the causation element directly.
Post-separation conduct is a hard cutoff in North Carolina: no act by the defendant supports a claim if it occurred after the spouses physically separated with the intent that the separation be permanent. Many affairs surface around the time of separation, so the timeline decides whether the conduct is actionable at all.
Consent or condonation is another route. If you knew about the affair and tolerated it, the defendant can argue you waived your right to sue. This comes up with open marriages or where the betrayed spouse discovered the affair and stayed in the marriage for a long stretch before filing.
Statute of limitations matters. In North Carolina, the claim must be filed within three years of the defendant’s last act giving rise to the cause of action. Other states set their own deadlines. Missing the window kills the case regardless of how strong the evidence is.
What You Could Actually Win
Successful plaintiffs recover compensatory damages for emotional suffering, humiliation, and loss of companionship. Courts weigh the depth of the anguish, the length of the affair, and any financial harm from the marital breakdown. Punitive damages are also on the table when the defendant’s conduct was especially brazen or malicious, and they can dwarf the compensatory portion.
In one North Carolina case, a Wake County judge awarded $30 million to a plaintiff: more than $10 million compensatory and $20 million punitive. Another North Carolina jury awarded $9 million in a separate alienation of affection case. Those are outliers. Most cases don’t produce eight-figure verdicts, many settle before trial, and the amount depends heavily on the defendant’s assets, the strength of the evidence, and how the jury reads the parties. A $30 million verdict against someone with modest assets is largely uncollectable.
How the Lawsuit Fits with Your Divorce
These are separate civil lawsuits against the third party, not part of the divorce itself. The divorce dissolves the marriage; the tort claim seeks money from the outsider who helped destroy it. Different proceedings, often different attorneys, sometimes different courts.
They influence each other anyway. Filing a tort claim can complicate and delay the divorce when both cases move at once. Discovery in the tort case may surface financial information or communications relevant to alimony and property division. Some plaintiffs use the tort claim as leverage in divorce negotiations, especially when the affair partner is financially connected to the cheating spouse.
Timing cuts the other way too. In North Carolina, the tort claim must be based on pre-separation conduct. Filing for divorce and physically separating before you’ve gathered evidence of interference can cost you the tort claim entirely.
If Your State Abolished These Claims
You can’t sue the affair partner, but the adultery can still shape your divorce. Many states allow fault-based divorce grounds, and adultery is one of the most common. It can also influence property division and alimony.
The effect varies. In some states, a spouse whose adultery caused the divorce may be barred from receiving alimony at all. In others, adultery is one factor among many when judges set support. A few treat it as largely irrelevant to money questions. The consequences fall on your spouse, not on the third party. That’s the trade-off in an abolition state: no recovery from the outsider, but potentially real leverage against your spouse in the divorce.
What Filing Actually Costs You
Before filing, understand what you’re stepping into. These cases are expensive, emotionally draining, and public.
Attorney fees can be substantial because the cases involve extensive discovery, depositions, investigator costs, and potentially a full jury trial. They’re not always taken on contingency. Many attorneys require hourly payment, and the case may take a year or more to resolve.
The emotional cost is real. These lawsuits put the most painful details of your marriage on public record. Depositions will cover your intimate relationship, your marital problems, and your spouse’s infidelity in clinical detail. If it goes to trial, a jury hears all of it. Some plaintiffs find the process retraumatizing rather than cathartic.
Watch out for counter-claims. If you take your grievances to social media or contact the defendant’s employer, you can expose yourself to claims for defamation, tortious interference with employment, or intentional infliction of emotional distress. Courts have recognized these counter-claims in heart balm cases, and they can turn plaintiff into defendant. The safer position is to let the lawsuit speak for itself and avoid public confrontation outside the courtroom.
What About Criminal Charges
Adultery is still technically a crime in roughly 16 states, most as a misdemeanor and a few as a felony carrying potential prison time. Prosecutions are extraordinarily rare. Most district attorneys have no interest in these cases, and many legal scholars consider the statutes dead letter law even where they remain on the books. Several states have moved to formally repeal their adultery laws. A criminal adultery statute is not a practical tool for holding an affair partner accountable.