Quick Answer: For the divorce itself, no. California is a no-fault state: the only grounds are irreconcilable differences or permanent legal incapacity to make decisions (Family Code section 2310), and evidence of specific acts of misconduct is generally inadmissible (section 2335). An affair does not change the equal division of community property or, by itself, the amount of spousal support. Cheating can matter in narrower ways: when community money was spent on the affair, when it affects the children, or when it overlaps with domestic violence. Those are the issues worth documenting.
Discovering an affair is painful, and it is natural to want the court to recognize what happened. California law deliberately keeps fault out of most of the divorce. Understanding where the line falls helps you spend your energy, and your legal budget, on the issues that can actually change the outcome.
California Is a No-Fault State
Family Code section 2310 allows a divorce on only two grounds: irreconcilable differences that have caused the irremediable breakdown of the marriage, or permanent legal incapacity to make decisions. You do not have to prove adultery, and your spouse cannot block the divorce by denying it. Section 2335 adds that, except as otherwise provided by statute, evidence of specific acts of misconduct is "improper and inadmissible" in a dissolution or legal separation case, including in depositions and discovery.
In Diosdado v. Diosdado (2002) 97 Cal.App.4th 470, the Court of Appeal summarized the policy: the family court may not look to fault in dissolving the marriage, dividing property, or ordering support.
Property Division Stays Equal
Under section 2550, the court divides the community estate equally unless the spouses agree otherwise in writing or on the record. An affair does not earn the other spouse a larger share. Our post on whether California is a 50/50 divorce state explains what "equal" covers.
When Affair Spending Does Matter
Money is where an affair most often becomes legally relevant. Spouses owe each other fiduciary duties in managing community property (sections 721 and 1100(e)). Several rules can apply when community funds went to an affair:
Gifts of community property. Under section 1100(b), a spouse may not make a gift of community personal property without the other spouse's written consent. Expensive gifts, travel, or rent paid for an affair partner from community funds can raise this issue.
Deliberate misappropriation. Section 2602 lets the court award the other spouse, from the misappropriating spouse's share, the amount the court finds was deliberately misappropriated to the exclusion of the other spouse's interest.
Breach of fiduciary duty. Section 1101 gives a spouse a claim for a breach that impairs their one-half interest in the community estate. Remedies under section 1101(g) include an award of 50 percent of an asset transferred in breach of the duty, plus attorney's fees and costs, and section 1101(h) allows up to 100 percent where the breach falls within Civil Code section 3294, which covers oppression, fraud, or malice.
The claim is about the money, not the infidelity. Bank and credit card records showing what was spent, when, and from which account are what make it work. Our posts on the fiduciary duties spouses owe each other and on hidden assets go deeper.
Spousal Support Is Based on Statutory Factors
Spousal support at judgment is set under the factors in section 4320, such as the length of the marriage, each spouse's earning capacity, and the marital standard of living. Infidelity is not one of the listed factors. Documented domestic violence is (section 4320(i)), and a domestic violence conviction can create a presumption against awarding support to the convicted spouse under section 4325. Our post on Family Code 4320 walks through each factor.
An affair can still affect support indirectly. If the paying spouse moved money to an affair partner, that money may bear on assets and ability to pay. And the timing of an affair sometimes becomes evidence in a dispute over the date of separation, which affects what is community property and how long the marriage lasted.
Custody Turns on the Child, Not the Affair
Custody decisions are based on the best interest of the child under section 3011, which focuses on the child's health, safety, and welfare, any history of abuse, habitual alcohol or drug abuse, and the child's contact with both parents. An affair by itself says little about parenting. It can become relevant when it affects the child, for example if a parent introduces a new partner who poses a safety risk, or if the conflict around the affair is pulling the child into adult disputes. Section 2335 also yields where another statute applies, and custody has its own statutory standards. Our post on what "best interest of the child" means explains the factors.
Can You Sue the Affair Partner?
Not for the affair itself. Civil Code section 43.5 abolished lawsuits for alienation of affection and criminal conversation in California. A claim to recover community property that was given away without consent is a different question and depends on the facts.
Infidelity Clauses in Prenups and Postnups
Some couples ask whether a prenup or postnup can impose a penalty for cheating. In Diosdado, spouses signed an agreement requiring a $50,000 payment by a spouse who was unfaithful. The Court of Appeal held it unenforceable because it imposed a fault-based penalty contrary to no-fault policy. Our posts on prenuptial agreements and transmutation agreements explain what marital agreements can do.
What to Do If You Discover an Affair
Gather financial records, especially joint account and credit card statements, before accounts are closed or changed.
Avoid accessing your spouse's private accounts or devices without legal advice. How evidence is gathered can create problems of its own.
Keep the children out of it. Messages and conversations about the affair can end up in a custody file.
Write down dates, including when the marriage, in your view, ended. That can matter for the date of separation.
Talk with a divorce lawyer before you confront, move out, or move money.
If the affair is part of a pattern of control, threats, or abuse, that is a different legal issue. Our post on coercive control explains when controlling behavior is domestic violence under California law.
Key Takeaways
No Fault Needed
California divorce grounds are irreconcilable differences or permanent legal incapacity, so proving an affair is not required.
Property Is Still Split Equally
An affair does not change the equal division of community property under Family Code section 2550.
Follow the Money
Community funds spent on an affair can support claims for reimbursement or breach of fiduciary duty.
Custody Focuses on the Child
Infidelity matters for custody only when it affects the child's health, safety, or welfare.
Frequently Asked Questions
Will I get more in the divorce if my spouse cheated? Not because of the affair itself. Community property is divided equally and support is based on the section 4320 factors. You may recover community money your spouse spent on the affair through a reimbursement or fiduciary duty claim.
Does adultery affect spousal support in California? Infidelity is not a factor in section 4320. Documented domestic violence is, and a domestic violence conviction can create a presumption against awarding support to the convicted spouse.
Can my spouse's affair partner be dragged into the divorce? The affair partner is not a party to the divorce. Records showing transfers of community funds can still be obtained through discovery when they are relevant to a financial claim.
Should I file for divorce right away after finding out about an affair? That depends on your goals, your finances, and your children. Getting advice before you act helps you protect records, accounts, and your position on custody.
An affair can end a marriage, but in California it rarely decides the divorce. To talk with Attorney Michael Geller about your situation, call The Geller Firm at 415-840-0570 to schedule a consultation.