SAFE stands for Secure Adultery Finances Exception, and there’s a reason we built it this way. If you’ve already read our prior post on why most anti-adultery clauses fail, you know the problem: defining adultery is messy, proving it is harder, and enforcing it often costs more than it’s worth. The SAFE clause exists to work around those realities rather than fight them. 

Should You Include a SAFE Clause?

As a general rule, most couples should avoid anti-adultery clauses altogether. They tend to add time, expense, and uncertainty to divorce proceedings—the exact opposite of what a prenup is supposed to do. Even when one spouse knows the truth, proving adultery in court is another matter entirely.

That said, some couples are insistent. They know they’ll feel more secure with some form of protection in place. If that’s you, there’s one threshold question you need to answer first:

Are you a couple of child-bearing age and capable of having children? If the answer is no, the SAFE clause won’t add meaningful value to your prenup. But if the answer is yes, this clause may be a good fit—if you understand how it works and why it’s structured the way it is.

What the SAFE Clause Actually Does

The SAFE clause is not about policing adult behavior. It’s about protecting children and preserving family resources.

Specifically, it addresses children born outside the marriage and the financial impact that can have on children of the marriage. At its core, the clause says something like this:

If, during the marriage, one spouse has a child with someone other than their spouse within ten (10) months of either party filing for divorce, that child is presumed to be the result of an adulterous relationship. As a result, the unfaithful spouse will receive only ___% of the marital assets and/or assume ___% of the marital liabilities.

The ten-month window can be adjusted. The asset split can be adjusted. The mechanics are flexible.

The point is simple: if adultery produces a child, the financial consequences shift.

Why This Isn’t “Punitive”

At first glance, this may feel punitive. But the goal isn’t punishment, it’s resource preservation.

There is a finite pool of marital assets. Those assets fund alimony, support children of the marriage, and—under the law—must also support children born outside the marriage. When a third child enters the picture, those resources get stretched thinner. And the people who usually pay the price are the children of the marriage.

Let’s start with a baseline scenario to illustrate:

1. Arthur and Betty are married and have one daughter, Cheryl.

2. Together, they build substantial assets through careful investing and saving.

3. They divorced simply because they grew apart. There was no adultery.

4. Arthur receives 50% of the marital assets through the divorce.

5. Betty receives 50% of the marital assets through the divorce.

6. When Arthur dies, Cheryl inherits Arthur’s 50%.

7. When Betty dies, Cheryl inherits Betty’s 50%.

Result: everything Arthur and Betty built together ultimately goes to Cheryl, precisely as intended.

Now, Add a Child Born Outside the Marriage

Let’s introduce two legal facts:

• A child born outside the marriage is entitled to child support.

• That child has inheritance rights.

With that in mind:

1. Arthur and Betty are married and have one daughter, Cheryl.

 2. They build significant marital assets together.

 3. Betty has an affair with another man.

4. Betty has a child, Delilah, with the other man.

 5. Arthur and Betty divorce.

6. Arthur gets 50% of the marital assets through the divorce.

 7. Betty gets 50% of the marital assets through the divorce.

8. Betty must use part of her share to support Delilah.

9. When Arthur dies, Cheryl inherits Arthur’s assets.

 10. When Betty dies, Cheryl and Delilah split Betty’s assets equally.

Result: The economic hit lands hardest on Cheryl.

Arthur had no say in the affair. Cheryl had no say in the affair. Yet the assets Arthur and Betty built together—intended for Cheryl—are permanently reduced to support a child born outside the marriage.

Delilah isn’t at fault either. She can’t be disinherited or punished for circumstances she didn’t choose. But that doesn’t change the financial reality.

How the SAFE Clause Fixes This

A properly drafted SAFE clause changes the divorce math before that damage occurs.

In this scenario, the clause might provide that Arthur—the non-cheating spouse—receives 75% of the marital assets. That allows Cheryl’s expected inheritance to remain intact through Arthur, while still ensuring Delilah receives the support and inheritance the law requires.

No prenup can fix the emotional fallout of adultery, especially when it creates a half-sibling. But a prenup can prevent avoidable financial harm to the children of the marriage.

Why a SAFE Clause is Worthwhile When Other Clauses Are Not

The SAFE clause sidesteps the three biggest problems with traditional anti-adultery provisions:

• Definition: No debates about what counts as cheating.

• Proof: No reliance on receipts, texts, or subjective interpretations.

• Ability to Pay: No court determination of ability to pay alimony because the SAFE clause is marital asset-based, not alimony-based.

A child conceived and born outside the marriage is an objective, legally recognized fact. That makes the clause far easier and less costly to enforce than any behavior-based alternative. In addition, the SAFE clause triggers a change in the division of marital assets, not an alimony recalculation. So, there is no judicial “ability to pay” analysis that makes many alimony-based anti-adultery clauses unenforceable or uncollectible.

That said, drafting a comprehensive SAFE clause correctly is very technical, and pitfalls must be avoided. It needs to be done carefully to be enforceable and fair—but when done right, it’s the rare anti-adultery clause that can actually deliver while remaining consistent with what couples want from a prenup.