Adultery and Fault Grounds Divorce

New York was the last state to adopt no-fault divorce. Since October 2010, a spouse can end a marriage by swearing that the relationship has broken down irretrievably for at least six months. That change did not erase the older grounds. Domestic Relations Law § 170 still lists adultery, cruel and inhuman treatment, abandonment, and imprisonment as independent grounds for divorce, and some clients still have good reasons to plead them. This page explains how each fault ground works, what you must prove, which defenses the other spouse can raise, and how fault does and does not affect money and custody.

The Seven Grounds Under Domestic Relations Law § 170

A New York court can grant a divorce only on one of the grounds set out in DRL § 170. Four are fault grounds. Two rest on a period of living apart under a separation judgment or agreement. The seventh is the no-fault ground.

1. Cruel and inhuman treatment: DRL § 170(1). Conduct that endangers the plaintiff's physical or mental well-being so that continuing to live together is unsafe or improper.
2. Abandonment: DRL § 170(2). The defendant left the plaintiff, or refused to live with the plaintiff, for one year or more.
3. Imprisonment: DRL § 170(3). The defendant was confined in prison for three or more consecutive years after the marriage.
4. Adultery: DRL § 170(4). A voluntary sexual act with a person other than the plaintiff after the marriage.
5. Living apart under a judgment of separation: DRL § 170(5). One year or more after a court decree of separation, with substantial performance of its terms.
6. Living apart under a written separation agreement: DRL § 170(6). One year or more after a properly executed and filed agreement.
7. Irretrievable breakdown: DRL § 170(7). The marriage has been broken for at least six months, as stated under oath by one spouse.

Most divorces filed today proceed under subdivision (7). If you want a plain explanation of that route, read our page on how no-fault divorce works in New York. The rest of this page addresses the fault grounds, with adultery first because it is the one clients ask about most.

Adultery Under DRL § 170(4)

The statute defines adultery narrowly. It is "the commission of an act of sexual intercourse, oral sexual conduct or anal sexual conduct, voluntarily performed by the defendant, with a person other than the plaintiff after the marriage of plaintiff and defendant." Three points follow from that language.

• Emotional affairs, flirtation, texting, and dating do not qualify. The statute requires a sexual act.
• The act must be voluntary. A spouse who was sexually assaulted has not committed adultery.
• The act must occur after the wedding. Conduct during the engagement is not a ground under § 170(4), although it may be relevant to an annulment based on fraud. Our page comparing annulment and divorce in New York covers that distinction.

Adultery was a Class B misdemeanor under Penal Law § 255.17 for more than a century. The Legislature repealed that section in 2024. The repeal matters in divorce practice because a paramour called as a witness can no longer refuse to answer on the ground that the testimony would expose them to criminal prosecution for the act itself.

How Adultery Is Proved in a New York Courtroom

Adultery is the hardest ground to prove, and the difficulty comes from an evidence rule rather than the substantive law. CPLR 4502(a) provides that a husband or wife "is not competent to testify against the other in an action founded upon adultery, except to prove the marriage, disprove the allegation of adultery, or disprove a defense after evidence has been introduced tending to prove such defense." In practice, you cannot take the stand and describe what you saw or what your spouse confessed. The proof must come from somewhere else.

Circumstantial evidence: opportunity and inclination

Direct eyewitness testimony of a sexual act is rare. New York courts accept circumstantial proof if it establishes both the opportunity to commit adultery and the inclination to do so. A hotel receipt alone shows opportunity. A hotel receipt combined with a private investigator's testimony that the defendant and a companion checked into a single room at 11 p.m., held hands in the lobby, and left together at 8 a.m. shows both. The trier of fact may then infer that the act occurred.

Sources of admissible proof

• Private investigator testimony: The most common route. A licensed investigator observes and documents the defendant and the third party, then testifies to those observations. Photographs and video are admitted through the investigator.
• Testimony of the third party: The paramour can be subpoenaed. Many deny everything, but a subpoena also reaches their phone records and travel documents.
• Documentary evidence: Credit card statements, hotel folios, airline records, dating-site profiles, and messages obtained through lawful discovery. Messages taken from a spouse's phone without authorization can create separate legal exposure, so the method of collection matters.
• Admissions: A defendant's out-of-court confession, if proven through a non-spouse witness or a document, is admissible. Courts will not grant a divorce on an uncorroborated confession alone because of the historic concern about collusive divorces.
• Medical evidence: A sexually transmitted infection contracted by the plaintiff, established through a physician, can corroborate other proof.

The plaintiff still testifies. CPLR 4502(a) permits testimony to prove the marriage and to rebut a defense once the defendant offers evidence of one. The plaintiff simply cannot supply the proof of the act itself.

Defenses to an Adultery Claim Under DRL § 171

DRL § 171 lists four defenses. If the defendant proves any of them, the court must deny the divorce on the adultery ground even if the adultery occurred.

1. Procurement or connivance

The plaintiff cannot obtain a divorce for adultery that the plaintiff arranged or encouraged. Example: A husband hires a person to seduce his wife so he can have a ground for divorce. The wife proves the arrangement through the hired person's testimony. The claim fails.

2. Forgiveness (condonation)

The statute bars the claim where "the offense charged has been forgiven by the plaintiff." Forgiveness may be proved "either affirmatively, or by the voluntary cohabitation of the parties with the knowledge of the fact." Example: A wife learns in January that her husband had an affair. She confronts him, he apologizes, and they resume living together and sharing a bed through the following autumn. In November she files for divorce on adultery. The husband pleads condonation and points to ten months of voluntary cohabitation after she knew. The defense will very likely succeed. Note that condonation is conditional: if the husband commits adultery again after the reconciliation, the earlier act is revived and can be pleaded along with the new one.

3. The five-year limitation

DRL § 171(3) bars the action where it "was not commenced within five years after the discovery by the plaintiff of the offense charged." DRL § 210 imposes the same five-year limit on adultery and cruel and inhuman treatment generally. The clock runs from discovery, not from the act. Example: A husband's affair took place in 2016. His wife found out on March 10, 2019, when she saw the messages. She must file the summons no later than March 10, 2024. If she files on April 1, 2024, the adultery ground is time-barred, although she may still proceed on irretrievable breakdown.

4. Recrimination

DRL § 171(4) bars the claim where "the plaintiff has also been guilty of adultery under such circumstances that the defendant would have been entitled, if innocent, to a divorce." Both spouses cannot use each other's adultery as a sword. Example: A wife sues on adultery. The husband counterclaims and proves through an investigator that the wife had her own affair the previous year. Neither spouse obtains a divorce on the adultery ground. In this scenario, the court will usually grant the divorce under § 170(7) instead.

Cruel and Inhuman Treatment Under DRL § 170(1)

This ground requires proof that the defendant's conduct "so endangers the physical or mental well being of the plaintiff as renders it unsafe or improper for the plaintiff to cohabit with the defendant." The Court of Appeals set the standard in Hessen v. Hessen, 33 N.Y.2d 406 (1974): the longer the marriage, the higher the degree of proof required. Incompatibility, coldness, and ordinary arguments are not enough. A single episode of serious physical violence can suffice. A pattern of verbal degradation, threats, or humiliation can suffice if the plaintiff proves an effect on health, often through a treating physician or therapist.

DRL § 210 gives this ground a five-year limitation as well. The plaintiff may rely on a course of conduct, and the court will consider acts within the five years before filing while allowing older conduct as background. Cruel and inhuman treatment overlaps heavily with family offense proceedings. If your spouse's conduct includes assault, harassment, or stalking, our pages on domestic violence in New York divorce and orders of protection during divorce explain the parallel remedies available in Supreme Court and Family Court.

Abandonment Under DRL § 170(2)

Abandonment comes in three forms, each requiring a full year before filing.

• Actual abandonment: The defendant physically left the marital home without justification, without the plaintiff's consent, and with no intent to return.
• Lock-out: The defendant excluded the plaintiff from the home, for instance by changing the locks.
• Constructive abandonment: The defendant refused sexual relations for at least one year, without justification, despite the plaintiff's repeated requests. Before 2010, this was the most commonly pleaded ground in uncontested cases because it required no third-party proof.

Worked example: A wife moved into a separate bedroom and refused all intimacy beginning June 1, 2023. Her husband asked to resume relations several times over the following months and was refused each time. He may file on constructive abandonment on or after June 1, 2024. If he filed on May 15, 2024, the ground would fail for want of the full year. Abandonment is a continuing wrong, so DRL § 210 exempts it from the five-year limitation.

Imprisonment Under DRL § 170(3)

The defendant must have been confined for three or more consecutive years after the marriage. Confinement before the wedding does not count. Like abandonment, this ground is exempt from the five-year limitation while the confinement continues, but the action must be brought within five years after release.

Comparison of the Fault Grounds

Does Fault Change the Financial Outcome?

Clients often assume that proving adultery will produce a larger share of the assets or more maintenance. New York law says otherwise in almost every case.

Equitable distribution

DRL § 236(B)(5)(d) lists the factors a court weighs when dividing marital property. Marital fault is not among them. The Court of Appeals in O'Brien v. O'Brien, 66 N.Y.2d 576 (1985), and the Appellate Division in Blickstein v. Blickstein, 99 A.D.2d 287 (2d Dep't 1984), held that fault is considered only where the conduct is so egregious that it shocks the conscience of the court. Attempted murder of a spouse has met that test. Adultery, standing alone, has not.

There is one indirect exception. DRL § 236(B)(5)(d)(12) directs the court to consider "the wasteful dissipation of assets by either spouse." If your spouse spent $40,000 of marital savings on hotels, gifts, and travel for a paramour, that spending can be charged against your spouse's share. The claim rests on the dissipation, not the affair, so you prove it through bank and credit card records rather than through an adultery ground. This is frequently the more productive use of investigative resources.

Maintenance

The post-divorce maintenance factors in DRL § 236(B)(6)(e) likewise omit fault. Courts apply the statutory formula and adjust for the listed factors, such as the length of the marriage and the payee's earning capacity. If you left the workforce to raise children and your spouse had an affair, your maintenance claim rests on the first fact and not the second. Our page for stay-at-home spouses in New York divorce explains how that claim is built.

Custody

Custody turns on the best interests of the child under DRL § 240. A parent's affair is relevant only if it affected the child: for example, exposing a young child to a series of overnight partners, or neglecting parenting duties to pursue the relationship. Judges are alert to attempts to use adultery evidence as a custody weapon and tend to react poorly to it.

Procedure for a Fault-Based Divorce

The action begins with a summons with notice or a summons and verified complaint filed in Supreme Court. DRL § 211 requires that the complaint be verified. The complaint must state the ground and, for adultery, the approximate time and place of the acts and the identity of the third party if known, or a statement that the identity is unknown. The plaintiff must satisfy the residency requirements of DRL § 230 as well.

Two procedural features distinguish fault cases from no-fault cases.

• Right to a jury: DRL § 173 grants a right to trial by jury on the issue of grounds. Either party may demand one. Jury trials on grounds are uncommon, but the demand itself changes the settlement dynamic.
• Bifurcation: The court may try grounds first and reserve the financial issues. If the plaintiff loses on grounds and has not pleaded § 170(7) in the alternative, the case ends without a divorce. For that reason, almost every complaint filed today pleads irretrievable breakdown alongside any fault ground.

In an uncontested case, the defendant signs an affidavit admitting the ground or defaults. Fault grounds are rarely pleaded in uncontested matters now because § 170(7) requires no admission by the defendant and no proof beyond the plaintiff's sworn statement.

When Pleading a Fault Ground Still Makes Sense

Given the cost of proof and the limited financial payoff, why plead fault at all? Several situations justify it.

• Separation actions: An action for separation under DRL § 200 has no no-fault ground. A spouse who wants a judicial separation rather than a divorce, often for religious or insurance reasons, must plead cruel and inhuman treatment, abandonment, neglect or refusal to support, or adultery.
• Religious considerations: Some clients need a civil finding of fault to support proceedings before a religious tribunal.
• Egregious conduct: Where the misconduct rises to the level that could affect equitable distribution, pleading the fault ground preserves the record.
• Leverage in negotiation: A well-documented adultery or cruelty claim can motivate a defendant to settle financial issues rather than face a public trial. Counsel must weigh that against the added fees and the risk of hardening positions. Couples who want to avoid that dynamic often turn to divorce mediation and proceed on irretrievable breakdown.

Practical Steps If You Suspect Adultery

1. Write down the date you first learned of the conduct. The five-year period under DRL § 171(3) runs from that date.
2. Do not resume marital relations with the intent of reconciling unless you have decided against pursuing the adultery ground. Voluntary cohabitation with knowledge is the core of a condonation defense.
3. Do not access your spouse's phone, email, or accounts without authorization. Improperly obtained evidence can be excluded and can expose you to liability.
4. Preserve financial records. Bank and credit card statements showing spending on a third party support a dissipation claim regardless of whether you plead adultery.
5. Consult counsel before hiring an investigator. The investigator's work product is only useful if it is gathered lawfully and the investigator is available to testify.

You can contact the Law Offices of Albert Goodwin by phone at 212-233-1233 or by email at [email protected].