What Is the Prenup Infidelity Clause?

An infidelity clause in a prenuptial agreement is a provision that attempts to impose financial consequences if a spouse commits adultery during the marriage. Couples in Manhattan and across New York City sometimes consider these clauses when significant assets or business interests are at stake. Under New York law, however, enforcement is uncertain. Although DRL § 236(B)(3) allows marital agreements to address maintenance and other terms of the marriage relationship, New York’s no-fault divorce framework and general public-policy concerns can make adultery-based penalty provisions difficult to enforce in practice.

At the Law Office of Richard Roman Shum, Esq., PLLC, Manhattan family law attorney Richard Roman Shum helps couples create prenuptial agreements tailored to their goals and grounded in New York law. Our NYC divorce lawyer can evaluate whether an infidelity clause makes sense for your specific situation and explain how New York courts have approached these provisions. 

This guide explains what an infidelity clause is, how it is drafted, whether New York courts enforce these clauses, what factors affect that outcome, and how to approach the conversation with your partner before the wedding. Call the Law Office of Richard Roman Shum, Esq., PLLC at (646) 259-3416 to discuss your prenuptial agreement.

What Is a Prenuptial Agreement Under New York Law?

Under New York DRL § 236(B)(3), a prenuptial agreement is a contract made before marriage that can govern issues such as property division, maintenance, and other terms of the marriage relationship. To be enforceable in a matrimonial action, the agreement must be in writing, subscribed by the parties, and acknowledged or proven in the manner required for a deed. If challenged, New York courts generally enforce duly executed prenuptial agreements unless the challenging party proves grounds such as unconscionability, fraud, duress, overreaching, or other inequitable conduct.

A typical prenuptial agreement covers property division, spousal support, and debt liability. It may also address business interests, inheritance rights, and how assets accumulated during the marriage will be treated. These provisions give both parties a clear financial framework before the wedding, which can reduce conflict and legal costs if the marriage later ends in divorce.

Couples in Manhattan frequently seek prenuptial agreements when one or both partners own real estate, hold significant business interests, or have children from a prior relationship. Contested prenuptial agreements that proceed to litigation are handled by the Matrimonial Part of the New York County Supreme Court, located at 60 Centre Street in lower Manhattan, making careful and precise drafting especially important.

What Does an Infidelity Clause in a Prenup Do?

An infidelity clause, sometimes called a “no-cheating clause” or “fidelity clause,” is a prenuptial provision that specifies financial consequences if one spouse commits adultery. A typical clause requires the offending spouse to pay a predetermined amount, forfeit certain assets, or give up entitlement to spousal support. The penalty serves both to deter infidelity and to provide some financial compensation to the non-offending spouse.

These clauses vary significantly in how they define infidelity. Some couples adopt a broad definition covering any romantic or sexual contact outside the marriage. Others limit the clause to specific physical acts, which requires more precise proof but ensures both parties fully understand what conduct triggers the penalty. The definition matters because it determines what evidence would be needed to establish a violation.

Including an infidelity clause also serves purposes beyond deterrence. It creates a structured opportunity for couples to discuss relationship expectations before marriage, and it signals mutual commitment to fidelity. For couples with substantial assets in professional and financial industries, these clauses can also provide some financial predictability in the event of a breakdown caused by adultery.

Key Takeaway: An infidelity clause specifies financial penalties for adultery within a prenuptial agreement. The clause’s definition of infidelity, evidentiary requirements, and penalty structure all affect whether it will carry meaningful weight if a dispute arises.

Family Law Attorney in Manhattan – Law Office of Richard Roman Shum, Esq., PLLC

Richard Roman Shum, Esq.

Richard Roman Shum, Esq. is a lifelong New Yorker and resident of Manhattan’s Lower East Side who has dedicated his practice to family law matters affecting individuals and families throughout New York. He brings years of legal experience to prenuptial agreements, divorce, and related proceedings, applying a focused and detail-oriented approach to each client’s unique situation.

Mr. Shum guides clients through the prenuptial agreement process with clarity and precision. He takes a pragmatic approach to each case, working to help clients achieve agreements that reflect their actual goals while holding up to legal scrutiny under New York law.

How Do You Draft an Infidelity Clause in a New York Prenuptial Agreement?

A valid infidelity clause should clearly define what conduct constitutes infidelity in the relationship. Couples may choose a broad definition that includes any romantic or sexual activity outside the marriage, or a narrower one confined to specific physical acts. A broader definition may be easier to satisfy in terms of evidence, but could capture conduct that one party does not view as a genuine breach.

The clause should also specify the standard of proof required to establish infidelity. Many prenuptial agreements apply the civil standard of a “preponderance of the evidence,” meaning it is more likely than not that infidelity occurred. A higher standard increases protection against unfounded claims but also raises the bar for the spouse who wants to enforce the clause.

Financial penalties must be reasonable to have any chance of surviving legal scrutiny. A penalty that forfeits all of one spouse’s marital assets for a single act of infidelity is more likely to be considered unconscionable by a court. Proportional penalties tied to the actual financial and emotional harm caused by the infidelity are more defensible.

Confidentiality provisions are also worth including. These limit how evidence of infidelity may be used and restrict access to sensitive personal information. Privacy protections are particularly relevant for clients in professional and financial industries where reputational concerns are significant, and they help prevent proceedings from becoming unnecessarily public.

Key Takeaway: An effective infidelity clause defines infidelity clearly, applies a specific proof standard, sets proportional financial penalties, and includes confidentiality protections. Vague definitions and extreme penalties both increase the risk that a court will decline to enforce the clause.

For guidance on drafting prenuptial provisions that are clear, proportional, and legally sound under New York law, contact the Law Office of Richard Roman Shum, Esq., PLLC at (646) 259-3416.

Do Infidelity Clauses Hold Up in New York Courts?

Infidelity clauses are among the most legally uncertain provisions a couple can include in a New York prenuptial agreement. Because New York is a no-fault divorce state under DRL § 170(7), courts do not require either party to prove wrongdoing to obtain a divorce. This framework shapes how judges view contract provisions that penalize specific marital conduct.

The New York appellate authority does not establish a bright-line rule that all infidelity clauses are unenforceable. But enforcement remains uncertain. New York courts strongly favor enforcement of duly executed marital agreements, while also applying heightened scrutiny to challenged maintenance-related provisions and refusing to enforce terms that are unconscionable or contrary to public policy. Because no-fault divorce has reduced the legal importance of proving adultery, an infidelity-based penalty provision may invite litigation over private conduct and face significant scrutiny if enforcement is contested.

There is also a risk that an infidelity clause could compromise the broader prenuptial agreement. If a court finds the clause unconscionable, it may disregard that provision, and in some cases, the presence of an extreme clause can be used as evidence that the agreement as a whole was overreaching. Discussing this risk with a prenuptial agreement attorney before finalizing the language is an important step.

What Factors Affect Whether a New York Court Will Enforce an Infidelity Clause?

New York Courts consider a number of issues when deciding whether an infidelity clause is enforceable:

Does the Clause Conflict with Public Policy?

New York courts are cautious about enforcing contract terms that regulate personal conduct within marriage. A clause that imposes financial consequences for behavior that a no-fault divorce law treats as legally irrelevant to the dissolution of a marriage is likely to face judicial resistance. Courts will examine whether the clause promotes marital discord or incentivizes litigation over private matters.

Is There Clear Evidence of Infidelity?

Even if a court were willing to consider enforcing the clause, proof would still be a major practical hurdle. The required proof standard may depend on the language of the agreement and the procedural posture of the case. For adultery claims generally, New York courts recognize that adultery is often proved through circumstantial evidence, and New York CourtHelp notes that evidence from someone other than the spouses is ordinarily needed when adultery is asserted as a divorce ground. In practice, proving a violation can require highly personal evidence and make the dispute costly and intrusive.

Are the Penalties Fair and Proportionate?

A court has the discretion to void provisions that appear unconscionable, meaning so one-sided or punitive that enforcement would be unjust. Financial penalties that are disproportionate to the actual harm caused, or that effectively strip the offending spouse of all assets, are particularly vulnerable to this analysis. Proportional penalties tied to specific and demonstrable harms have a better chance of surviving judicial scrutiny.

What Is the Context of the Overall Agreement?

How the infidelity clause fits within the prenuptial agreement as a whole also matters. A clause embedded in a balanced, fair agreement, entered into by both parties with independent legal counsel and adequate time for review, stands a stronger chance of being upheld. The Matrimonial Part of Manhattan’s New York County Supreme Court has broad discretion in evaluating these factors, and outcomes can vary considerably from case to case.

Factors Affecting Infidelity Clause Enforceability in New York

Factor	Court’s Concern	Effect on Enforceability
Public Policy	Conflicts with no-fault divorce principles under DRL § 170(7)	Reduces the likelihood of enforcement
Evidence Standard	Adultery allegations are fact-intensive and may require corroborating or circumstantial evidence, depending on the agreement and procedural posture	Can be costly, intrusive, and difficult to litigate
Penalty Proportionality	Must not be unconscionable or grossly one-sided	Disproportionate penalties likely voided by the court
Clause Clarity	Vague definitions create interpretation disputes	Precise definitions improve enforceability
Overall Agreement Fairness	The agreement as a whole must be equitable	An unfair agreement weakens all individual provisions

Key Takeaway: Whether a New York court enforces an infidelity clause depends on its alignment with public policy, the quality of available evidence, the proportionality of the penalties, and the overall fairness of the prenuptial agreement. No outcome is guaranteed without careful drafting and legal guidance.

For guidance specific to your prenuptial agreement, contact the Law Office of Richard Roman Shum, Esq., PLLC at (646) 259-3416.

What Role Does an Infidelity Clause Play in New York Divorce Proceedings?

Under New York law, spousal support is determined by DRL § 236(B) based on financial factors such as each spouse’s income, earning capacity, and the length of the marriage. Marital misconduct, including infidelity, is not a standard factor in those calculations. An infidelity clause in a prenuptial agreement does not automatically alter what a spouse receives in support or assets when a marriage ends.

If a court chooses to enforce the clause, the financial penalties it specifies could effectively reduce the offending spouse’s share of support or assets. This would be an exception rather than the rule. The burden of proving infidelity rests on the spouse asserting the claim, and that spouse must satisfy whatever evidentiary standard is set in the agreement during contested proceedings.

If both spouses committed infidelity, many prenuptial agreements address this by voiding the clause or treating the violations symmetrically to cancel out the penalties. Without such a provision in the agreement, a court in a no-fault divorce state like New York is unlikely to impose financial penalties on either party based on mutual fault.

Talk to a Manhattan Family Law Attorney Today

A prenuptial agreement that includes an infidelity clause raises legal questions that go beyond personal preferences. The enforceability of the clause under New York’s no-fault divorce framework, the evidentiary standards required to trigger it, and the risk that an extreme clause could compromise the broader agreement are all considerations that require careful legal guidance.

Richard Roman Shum has guided clients through prenuptial agreements involving complicated and sensitive provisions, including infidelity clauses. At the Law Office of Richard Roman Shum, Esq., PLLC, our prenuptial agreement attorney works with clients to draft provisions that are clear, proportional, and aligned with New York law. 

Call the Law Office of Richard Roman Shum, Esq., PLLC at (646) 259-3416 to schedule a consultation. Our office is located at 20 Clinton St., New York, NY 10002, serving clients throughout Manhattan and the surrounding areas. Richard Roman Shum can advise you on whether a prenuptial infidelity clause is worth including, how it may be treated under New York law, and what language may help reduce the risk of future disputes.

from Law Office of Richard Roman Shum, Esq. https://www.romanshum.com/blog/what-is-the-prenup-infidelity-clause/