Below is a comprehensive discussion of the crime of adultery in the Philippines, particularly under the Revised Penal Code (RPC). This article covers the definition, elements, penalties, procedure, and relevant jurisprudence. While this overview is extensive, please note that laws and their interpretation may change over time. Always consult updated legal references or seek professional legal advice for specific situations.

1. Legal Basis

In the Philippines, adultery is primarily governed by Article 333 of the Revised Penal Code (Act No. 3815, as amended). Adultery is classified as a crime against chastity under Philippine criminal law.

Article 333 of the Revised Penal Code

Adultery is committed by any married woman who shall have sexual intercourse with a man not her husband and by the man who has carnal knowledge of her, knowing her to be married, even if the marriage be subsequently declared void.

2. Definition and Nature of the Crime

Adultery is the voluntary sexual intercourse between a married woman and a man who is not her husband. Philippine law treats adultery differently from concubinage (Article 334 of the RPC), which applies to a married man who cohabits or maintains a paramour under certain circumstances. Adultery can only be committed by:

A married woman who has sexual relations with a man other than her husband.
The male partner, provided he knows that the woman is married.

Classification as a Private Crime

Adultery is considered a private crime, which means:

Only the offended party (i.e., the husband in the case of adultery, or the wife in the case of concubinage) can file a complaint.
It cannot be prosecuted except upon a sworn written complaint by the offended spouse.
The complaint must include both the erring spouse and the paramour (if identifiable). Failing to include one or the other without a valid justification can result in dismissal of the complaint.

3. Elements of Adultery

To secure a conviction for adultery under Philippine law, the following elements must be proven:

The woman is married.
The existence of a valid marriage at the time the act occurred must be established.
There is sexual intercourse between the married woman and a man who is not her husband.
Mere affectionate acts or dates are not enough; actual carnal knowledge must be proven.
The man knows that the woman is married.
If the man truly did not know or had no reason to believe that the woman was married, he might have a valid defense.
The act is voluntary.
There must be mutual consent; coerced acts or sexual assault would be treated differently under the law.

4. Penalty for Adultery

The penalty for adultery under Article 333 of the RPC is prisión correccional in its medium and maximum periods, which ranges generally from:

2 years, 4 months, and 1 day to 6 years.

Both the married woman and her paramour, upon conviction, may be subject to the same penalty. The court can impose fines and ancillary penalties depending on the circumstances, but imprisonment is the principal penalty.

5. Distinguishing Adultery from Concubinage

Philippine criminal law treats adultery and concubinage as separate offenses:

Adultery (Art. 333):
- Committed by a married woman who engages in sexual intercourse with a man not her husband.
- Requires proof of a single act of sexual intercourse.
Concubinage (Art. 334):
- Committed by a married man under specific circumstances (cohabitation with a paramour in the conjugal dwelling, or maintaining her in a notorious relationship, or having sexual intercourse under scandalous circumstances).
- Typically more difficult to prove, as it requires proof of a “notorious” relationship or scandalous conduct, or cohabitation in the conjugal home.

A key difference is that adultery can be proven by showing one specific act of sexual intercourse, whereas concubinage generally requires proof of cohabitation, multiple acts, or scandalous circumstances over a period of time.

6. Procedure and Jurisdiction

6.1 Filing a Criminal Complaint

Because adultery is a private crime, the offended spouse (the husband) must personally file a sworn complaint against both his wife and the alleged paramour. The complaint must be filed with:

The Office of the City Prosecutor or
The Office of the Provincial Prosecutor, depending on the location where the crime was committed.

6.2 Inclusion of Both Parties

It is a requirement that the husband must charge both the wife and her paramour in the same complaint. If he fails to do so, and he does not provide a valid legal ground (such as the paramour being unidentified or unascertained), the complaint may be dismissed.

6.3 Evidence Required

Proof of Marriage: A certified true copy of the marriage contract or any other substantial evidence of marriage.
Proof of Sexual Intercourse: This may come from eyewitness testimony, text messages, hotel receipts, photographs, private investigator reports, or admissions, among others. Direct evidence (e.g., being “caught in the act”) is the strongest, but circumstantial evidence can also suffice if it leads to a moral certainty of guilt.
Proof that the Man Knew the woman was married. This can be inferred from circumstances, such as statements, introductions, or prior knowledge of the marriage.

6.4 Time Limit (Prescription)

Under Philippine law, adultery prescribes in five years (Article 91, RPC). This period is counted from the date of the commission of the offense or from the time the offense was discovered if it remained hidden. If the husband does not institute the action within the prescriptive period, the right to prosecute is extinguished.

7. Defenses and Extinguishment of Criminal Liability

7.1 Condonation or Forgiveness

Adultery is subject to condonation, meaning that if the offended spouse expressly or impliedly forgives the adulterous spouse and/or the paramour, the crime may no longer be prosecuted. Forgiveness can be:

Express: Clear statement (in writing or verbally) forgiving the offense.
Implied: Actions by the husband that manifest forgiveness, such as resuming conjugal relations with full knowledge of the wife’s adulterous act.

Once there is valid forgiveness or condonation, it generally extinguishes the husband’s right to file a criminal case for adultery.

7.2 Consent

Similar to forgiveness, if the husband consented to the adulterous act (e.g., he encouraged or facilitated it), he loses the right to prosecute.

7.3 Other Possible Defenses

Lack of Sexual Intercourse: Adultery requires proof of actual carnal knowledge.
Lack of Knowledge of Marriage: For the paramour, proving that he genuinely did not know the woman was married (and had no reasonable means to discover it) is a defense.
Void Marriage: If the marriage was declared void before the adulterous act, adultery cannot be charged. However, note that a subsequent declaration of nullity or annulment does not absolve prior adulterous behavior.

8. Relationship to Civil Actions (Annulment or Legal Separation)

Adultery as a Ground for Legal Separation: Under the Family Code (Executive Order No. 209), adultery is a ground for legal separation. If the husband wishes to file for legal separation or even an annulment in some cases, he can use the same evidence to prove marital misconduct. However, the criminal action for adultery and a civil action for legal separation are distinct processes.
Effect on Property Relations and Custody: If found guilty of adultery, it may influence the court’s ruling in civil cases regarding spousal support, custody of children, or property rights. Adultery alone, however, does not automatically deprive a spouse of custody but can be a factor in determining the best interests of the children.

9. Procedural Nuances and Practical Considerations

Public Scandal and Privacy: Since adultery cases can involve highly personal matters, many cases never reach trial. Some are settled out of court for privacy or to avoid public scandal.
Burden of Proof: The prosecution must establish guilt beyond reasonable doubt. Evidence of mere suspicious behavior is insufficient; the proof must be compelling.
Joinder of Offenses: The offended spouse cannot file separate complaints for each act of adultery unless they are distinctly proven separate crimes (i.e., repeated acts on different dates, each with sufficient evidence).
Potential Impact on Family: Prosecuting a criminal case for adultery can have significant emotional and financial repercussions for all involved, including children.

10. Relevant Jurisprudence and Legal Updates

People v. Hernandez, G.R. No. 26808 (1968) – Affirmed that adultery is proven by showing the existence of sexual relations between a married woman and a man not her husband, and that suspicion alone is not enough.
People v. Vicente, 70 Phil. 28 (1940) – Explained the concept of implied pardon/condonation when the offended spouse continues living with the offending spouse.
Recent Developments: There have been various proposals to decriminalize adultery and concubinage or to reform the laws to remove gender biases. However, as of this writing, adultery remains criminalized in the Philippines. Always check for updated legislative developments.

11. Frequently Asked Questions (FAQs)

Can a wife also file a case of adultery against her husband?
No. Under current laws, if a husband engages in extramarital affairs, the applicable crime is concubinage, not adultery. The wife would have to file concubinage charges, which have different legal elements.
If I forgive my spouse, can I still file a criminal case later?
Generally, if you have already forgiven (condoned) the act, you lose the right to prosecute. Forgiveness can be implied, so exercising caution in your actions is crucial if you wish to retain the right to file a case.
Does a declaration of nullity or annulment affect a prior act of adultery?
A subsequent declaration of nullity or annulment does not absolve acts of adultery committed before the decree. The marriage was valid until declared void by the court, so any act of adultery prior to that date can still be prosecuted (subject to the statute of limitations and other defenses).
Can adultery be settled out of court?
Since it is a criminal offense, the court ultimately decides on dismissal or conviction. However, the private complainant’s decision to withdraw or not continue can lead to the dismissal of the case because it is a private crime. Sometimes, parties reach extrajudicial settlements to avoid public exposure.
Is evidence such as text messages or social media posts enough to prove adultery?
These can be used as circumstantial evidence but generally need to be strong and corroborated. There must be convincing proof of actual sexual intercourse. Text messages or chats implying an affair, while indicative, may not, on their own, suffice to prove carnal knowledge beyond reasonable doubt.

12. Conclusion

Adultery in the Philippines remains a serious criminal offense under the Revised Penal Code, grounded in the country’s traditional view of protecting the sanctity of marriage. As a private crime, it can only be prosecuted upon the initiative of the offended spouse, who must provide solid proof of sexual intercourse and knowledge of the marriage. Forgiveness, consent, or the expiration of the prescriptive period are primary defenses.

Because of the intimate and sensitive nature of such cases, as well as potential implications for family and privacy, pursuing an adultery charge should be carefully weighed. Consultation with a qualified legal professional is indispensable for anyone considering legal action or facing charges, to ensure proper guidance through the evidence gathering, filing, and trial processes, and to explore possible civil remedies or alternative dispute resolution.

Disclaimer: This article is for general informational purposes and should not be taken as legal advice. For case-specific guidance, it is always best to seek the assistance of a licensed attorney experienced in family law and criminal litigation in the Philippines.