Does cheating change anything?

The short answer

Mostly, no. In Canada, adultery is one ground for divorce, but the law says misconduct cannot be considered for spousal support, property is divided by formula, and past conduct only matters for parenting if it affects the children. Money spent on an affair can sometimes be accounted for. Most US states are no-fault too, but a few, such as Virginia and North Carolina, can still let adultery affect alimony. Knowing this early can save you a long, expensive fight.

You found out. Maybe from a message on a phone, maybe from a friend, maybe from your spouse. Along with the shock comes a sense that there must be some consequence: that the person who broke the marriage should not walk away with half of everything.

It is a completely human reaction. The honest legal answer, in most of Canada and the US, is that the affair itself changes very little about how property, support and parenting are decided. This guide explains why, where the exceptions are, and what you can usefully do instead. It is general information, not legal advice, and the rules differ by province and state.

Divorce: adultery is a ground, but rarely the one that matters

In Canada, the Divorce Act says a marriage has broken down, which is the only basis for a divorce, if one of three things is shown:

the spouses have lived separate and apart for at least one year;
the other spouse has committed adultery; or
the other spouse has treated you with physical or mental cruelty that makes living together intolerable.

So adultery can let you apply for a divorce without waiting a year. But it has to be proved if your spouse disputes it, and it does not change anything else about the outcome. The one-year separation ground needs no proof of anyone's behaviour, and you can sort out parenting, support and property during that year anyway. Our guide to separated, legally separated and divorced explains the difference.

In the US, the Legal Information Institute at Cornell notes that all states now recognise no-fault divorce, and many have adopted pure no-fault, where fault grounds are no longer available. California is one: its Family Code allows divorce only for irreconcilable differences or permanent legal incapacity to make decisions. Other states still offer fault grounds, including adultery, alongside no-fault.

Spousal support: misconduct is off the table in Canada

The Divorce Act is explicit. In making a spousal support order, "the court shall not take into consideration any misconduct of a spouse in relation to the marriage." The Supreme Court of Canada confirmed this in Leskun v. Leskun (2006): misconduct, as such, is off the table.

The same decision draws an important line. There is a difference between the misconduct and its emotional consequences. The Court gave the example of abuse leading to depression so serious that the person cannot work. Those consequences can be highly relevant to whether support is owed, how much and for how long. The focus is on the consequences, not on assigning blame. So if the end of your marriage has genuinely affected your ability to earn, that can be part of a support claim. The affair itself is not.

Provincial support laws apply to unmarried couples and to married couples not divorcing, and they have their own wording. Check with a lawyer in your province. For how support is actually calculated, see our spousal support guide and the FairWell calculators.

Property: a formula, with a narrow exception for money

Canadian property regimes divide by formula, not by fault. Ontario's equalisation of net family property is the clearest example. A court can order an unequal split under section 5(6) of Ontario's Family Law Act only if equal division would be unconscionable, with regard to listed factors, one of which is a spouse's intentional or reckless depletion of their net family property.

That is where an affair can sometimes matter: not the affair, but family money spent on it. A summary of the Ontario case Cosentino v. Cosentino (2015) on separation.ca shows how high the bar is. The wife argued that her husband's affairs justified an unequal division. The court held that section 5(6) was "very tightly drawn" to exclude matrimonial misconduct of that kind, that there was no evidence the affairs had any significant effect on the couple's property, and that unconscionability means more than hardship or unfairness.

In practice, if you can show that significant shared money went on hotels, gifts, trips or a second household, raise it with your lawyer. It is an accounting question about money, and it needs documents. Our guide to hidden assets warning signs covers how to trace it.

US states use similar ideas. North Carolina's equitable distribution law, for example, lets a court consider acts of either party to waste, neglect or convert marital property between separation and division.

Where fault still counts in the US

A minority of US states still let adultery affect support, and sometimes property. Two examples from the statutes themselves:

Virginia. Adultery before the last separation is a ground for divorce. Under Virginia Code section 20-107.1, no permanent support can be awarded to a spouse against whom an adultery ground exists, unless the court finds by clear and convincing evidence that denying support would be a manifest injustice. Courts must also consider the circumstances that contributed to the breakdown, specifically including adultery, when deciding support, and similar wording appears among the factors for dividing property.
North Carolina. If the dependent spouse engaged in illicit sexual behaviour during the marriage and before separation, the court shall not award them alimony. If the supporting spouse did, the court shall order alimony to a dependent spouse. If both did, it is up to the court. Behaviour the other spouse condoned is not considered, and either spouse can ask for a jury to decide the misconduct question.

These rules are specific, technical and change over time. If you live in a state that considers fault, speak to a lawyer there before you decide how to file, because the choice can affect cost and privacy as much as outcome.

Children: what matters is the effect on them

Under the Divorce Act, in deciding a child's best interests the court shall not consider the past conduct of any person unless it is relevant to their parenting. An affair does not, on its own, make someone a worse parent in the eyes of the law. It might become relevant if, for example, it exposed children to harm or a parent's new relationship is affecting their care. That is a question about the children, not about the marriage.

Child support is also untouched. In Canada the base amount comes from the Federal Child Support Tables, using the paying parent's income and province, which you can look up on the Justice Canada child support look-up.

What children need to hear about the affair is usually nothing. Our guide on how to tell children about separation helps you explain the change without putting them in the middle.

"Mum and Dad have decided to live in different homes. It is a grown-up decision, it is not because of anything you did, and we both love you."

"Ask your father why we are splitting up. Ask him who he has been seeing."

Practical steps in the first few weeks

Discovering an affair often comes with a rush to act. A few steps protect you without inflaming things:

Copy the financial records you already have access to: joint bank and credit card statements, tax returns, mortgage and investment statements. You will need them for disclosure whatever happens. The financial disclosure checklist lists what to gather.
Note unusual spending with dates and amounts, rather than accusations. If it turns out to be significant, a lawyer can raise it.
Write down your separation date. It matters for property and for the one-year divorce ground. See why the separation date matters.
Stay off social media about it. Posts can be used in court and can reach your children. Our guide to social media during separation explains why.
Do not make big decisions in the first week about moving out, money or the children, unless safety requires it.

What to do with the anger

None of this makes the betrayal smaller. It just means a court is the wrong place to look for acknowledgement of it. People who litigate to punish usually spend money they need and years they will not get back, and the outcome on money and children rarely changes. A counsellor can help with the hurt; see anger and resentment after separation and finding a therapist. Put your energy into full financial disclosure, a fair support figure and a parenting plan that works.

When to get professional help

You believe significant family money was spent on the affair.
You live in a US state that considers fault for alimony or property.
The end of the marriage has affected your health or ability to work.
There are concerns about the children's safety with a new partner.

The FairWell directory lists family lawyers by province and state. If you want to sort out the rest calmly, Separation Agreement Prep organises disclosure, support and parenting into a draft for review.

This guide is general information, not legal advice. Family law differs by province and state and changes over time. Confirm your position with a lawyer where you live before relying on it.

Sources

Common questions

Will I get more spousal support because my spouse cheated?

Not in Canada. The Divorce Act says misconduct in the marriage cannot be considered for spousal support. The emotional consequences can matter, for example if the breakdown affected your health or ability to work. A few US states, such as Virginia and North Carolina, do let adultery affect alimony.

Does an affair change how property is divided?

Usually not. Property is divided by formula. The narrow exception is money: if significant family funds were spent on the affair, a court may account for it, but in Ontario the test for an unequal split is very high.

Can I get a faster divorce because of adultery?

In Canada, adultery is a ground that avoids the one-year wait, but it must be proved if disputed. Many people use the one-year separation ground and settle everything else in the meantime. Most US states offer no-fault divorce.

Can cheating affect custody?

Not on its own. Canadian courts cannot consider past conduct unless it is relevant to parenting. It matters only if it affected the children, for example by exposing them to harm.

Should I tell the children about the affair?

Generally no. Children need to know the separation is not their fault and that both parents love them. Details of adult relationships put them in the middle.

Turn the focus to what you can actually decide

The free assessment asks a few questions about where you live, children and money, and points you to the next practical step, whether that is disclosure, support or a parenting plan.

Start the free assessment

This guide is general information for parents, not medical, psychological or legal advice. It draws on published research and guidance from recognised health and family justice bodies, listed under Sources. Every child and family is different. If you are worried about your child or yourself, talk to your family doctor or a qualified professional. FairWell can help you find one through the professional directory. How we write and check our guides.