Below is an overview of the legal landscape surrounding marital infidelity in the Philippines, focusing on criminal liabilities for adulterous or concubinary relationships under the Revised Penal Code (RPC), possible civil and family law implications, and practical considerations. This information is provided for general educational purposes and does not constitute legal advice. For specific concerns, it is best to seek counsel from a qualified attorney.

1. The Philippine Legal Framework

1.1 The Revised Penal Code

In the Philippines, marital infidelity can be prosecuted as a crime under the Revised Penal Code (RPC). Two distinct criminal offenses address infidelity:

Adultery (Article 333, RPC) – applies to a married woman who engages in sexual intercourse with a man other than her husband, and also holds the other man criminally liable.
Concubinage (Article 334, RPC) – applies to a married man who cohabits with a woman other than his wife under specific, more stringent circumstances (e.g., bringing the other woman into the conjugal dwelling, or engaging in scandalous conduct with her elsewhere).

1.2 The Family Code

The Family Code of the Philippines (Executive Order No. 209, as amended) primarily governs marriage and family relations. While it does not directly penalize infidelity (that is in the RPC), it provides grounds and procedures for legal separation, annulment, and nullity of marriage, which may be invoked if marital infidelity causes irreparable breakdown of the marriage or is symptomatic of deeper issues (e.g., psychological incapacity).

1.3 Other Relevant Laws

Republic Act No. 9262 (Anti-Violence Against Women and Their Children Act of 2004) – Psychological violence, including acts that cause emotional or psychological suffering (often present in marital infidelity scenarios), can be a basis for legal action under RA 9262. Although it is not a direct criminalization of infidelity, the emotional harm inflicted by a spouse’s infidelity could be argued as psychological violence or abuse.

2. Adultery: Definition, Elements, and Penalties

2.1 Definition

Under Article 333 of the RPC, adultery is committed by:

A married woman who voluntarily has sexual intercourse with a man not her husband; and
The man who knows that she is married.

2.2 Elements of the Crime

To secure a conviction for adultery, the following must be proven beyond reasonable doubt:

Existence of a valid marriage between the accused woman and her legal husband.
Sexual intercourse took place between the accused woman and another man.
The man was aware of the woman’s marital status at the time of the sexual act.

2.3 Penalties

Adultery is punishable by prisión correccional (which generally ranges from 6 months and 1 day to 6 years).
Both the married woman and her co-accused male partner are penalized if found guilty.

2.4 Important Procedural Notes

Only the offended spouse can file a criminal complaint for adultery. Third parties cannot initiate the action.
The offended spouse (the husband in an adultery case) must include both the wife and her paramour in the complaint. Failing to include one or the other is not allowed.
If the offended spouse condones or pardons the infidelity (e.g., resumes marital relations or otherwise forgives the act), this can bar the criminal action.
A legal impediment exists when the spouse who accuses also commits the same crime (known as “pari delicto”). If the husband himself was also committing concubinage, the courts may see it as grounds to dismiss the adultery complaint.

3. Concubinage: Definition, Elements, and Penalties

3.1 Definition

Under Article 334 of the RPC, concubinage is committed by:

A married man who either:
- Keeps a mistress in the conjugal dwelling;
- Has sexual intercourse under scandalous circumstances with a woman not his wife; or
- Cohabits with her in any other place;
The mistress is similarly criminally liable if she is aware of the married man’s status.

3.2 Elements of the Crime

To convict for concubinage, the prosecution must show:

Existence of a valid marriage between the accused man and the offended party (his wife).
The man committed one of the enumerated acts (keeping a mistress in the conjugal home, scandalous sexual conduct, or cohabiting in another place).
Proof that the relationship or circumstances constitute concubinage (the standard is high and typically requires evidence of continuous, open cohabitation or scandalous public conduct).

3.3 Penalties

The husband convicted of concubinage faces prisión correccional in its minimum and medium periods (i.e., from 6 months and 1 day to 4 years and 2 months).
The concubine (the woman involved) can be punished with destierro (exile), which means she is required to stay away from certain designated places (typically a specified radius around the offended wife).

3.4 Procedural Notes

Only the offended wife can file the complaint for concubinage.
The wife must include both her husband and his concubine in the complaint.
As with adultery, if the wife forgives or condones her husband’s infidelity after discovering it, this can bar the criminal action.

4. Differences Between Adultery and Concubinage

Criminal Acts:
- Adultery punishes every single act of sexual intercourse. Each act can be a separate count.
- Concubinage is punished as an ongoing relationship involving cohabitation or scandalous circumstances. It is harder to prove since mere proof of sexual acts without cohabitation or scandalous conduct may not suffice.
Who Is Punished:
- Adultery: The married woman and the other man.
- Concubinage: The married man and his concubine.
Evidentiary Standards:
- In adultery, the requirement of proof of sexual intercourse can be established by circumstantial evidence (e.g., testimonies, hotel registrations, photos, text messages, etc.).
- In concubinage, it must be shown that the husband was cohabiting or was engaged in scandalous conduct in addition to proving sexual relations.
Penalties:
- Adultery: prisión correccional (6 months and 1 day to 6 years) for both parties.
- Concubinage: prisión correccional in its minimum and medium periods (6 months and 1 day to 4 years and 2 months) for the husband, and destierro for the concubine.

5. Civil and Family Law Implications

Grounds for Legal Separation
Under the Family Code (Article 55), repeated physical violence or grossly abusive conduct, sexual infidelity, or perversion are grounds for legal separation. Note that legal separation does not sever the marriage bond but permits spouses to live separately and settle certain property matters.
Grounds for Annulment or Nullity of Marriage
- Typically, infidelity alone is not a ground for annulment or declaration of nullity. The recognized grounds (e.g., lack of parental consent, psychological incapacity, fraud, etc.) do not directly include infidelity.
- However, severe and repeated infidelity might be invoked as evidence of “psychological incapacity” under Article 36 if it shows an incapacity to comply with essential marital obligations.
Effects on Property
If found guilty in a criminal case or upon a decree of legal separation, the offending spouse might lose certain rights in property relations, including possible forfeiture of some benefits in favor of the children or the innocent spouse.
Child Custody and Support
Regardless of infidelity issues, courts typically prioritize the best interests of the child when determining custody. Infidelity alone does not bar a spouse from custody, but the court may consider moral fitness and overall circumstances.

6. Psychological Violence under RA 9262

Definition: Psychological violence in RA 9262 covers acts that cause mental or emotional suffering. An extramarital affair may fit if it inflicts emotional anguish or mental suffering on the lawful wife or children.
Relief: A victim of psychological violence may seek protection orders (Barangay Protection Orders, Temporary/Permanent Protection Orders from the court) and file criminal charges.
Punishment: Conviction of psychological violence under RA 9262 entails penalties ranging from a few months to years of imprisonment, depending on the gravity of the abuse.

7. Initiating Legal Action

Gather Evidence:
- Documentary proof (emails, text messages, photos, videos, receipts, hotel records) can be crucial.
- Witness testimony or admissions from the unfaithful spouse can also support a case.
Consult a Lawyer:
- Seek legal advice on the merits of an adultery or concubinage complaint or a possible case under RA 9262.
- Weigh the criminal aspect alongside possible civil or family law remedies (e.g., legal separation, petitions for custody, child support).
Filing the Case:
- The offended spouse must file a sworn complaint-affidavit with the Office of the City or Provincial Prosecutor.
- If the Prosecutor’s Office finds probable cause, it files an Information in court.
- The case then proceeds through trial unless settled, dismissed, or withdrawn.
Timing and Condonation:
- Once the offended spouse forgives the adulterous or concubinary conduct (especially in writing or by resuming marital relations), prosecution is generally barred.
- Quick and consistent action is advisable if one intends to pursue a case.

8. Practical and Personal Considerations

Difficulty of Proof:
- Adultery cases are often easier to prove because each act of intercourse could be alleged if documented or witnessed.
- Concubinage is more complex, often requiring proof of cohabitation or scandalous circumstances.
Social and Emotional Costs:
- Criminal litigation can be lengthy, expensive, and emotionally draining for all involved.
- Reconciliation becomes more difficult once criminal allegations are filed.
Privacy Concerns:
- Court trials are generally public. The details of one’s private life can be exposed during proceedings, sometimes affecting social and familial relationships.
Possibility of Out-of-Court Settlements:
- Some parties prefer to settle extrajudicially for the sake of preserving family harmony or mitigating further emotional and financial strain.
Use of RA 9262 (Psychological Violence):
- This route can be suitable when the infidelity has deeply traumatized the spouse or children.
- Typically, a protective order can be sought quickly if emotional or psychological harm is proven.

9. Conclusion

In the Philippines, there are clear legal frameworks criminalizing marital infidelity—adultery for the unfaithful wife and her paramour, and concubinage for the unfaithful husband and his mistress. However, these laws are often criticized for being outdated or gender-biased, imposing different requirements and penalties depending on the spouse’s gender. Beyond these criminal actions, the victimized spouse may have remedies under the Family Code (legal separation, possible civil implications) or under RA 9262 (if psychological violence is evident).

Any person facing marital infidelity should:

Consult a lawyer for personalized advice and guidance.
Carefully consider whether criminal prosecution, civil remedies, or other avenues (e.g., counseling, mediation) are appropriate.
Gather evidence thoroughly, since proving adultery or concubinage requires meeting exacting standards.
Be mindful of emotional, financial, and social ramifications of pursuing a court case.

While the law provides formal means to seek justice, the ultimate approach often involves a combination of legal, financial, emotional, and family considerations. Seeking professional counseling or therapy for both spouses and children, if any, may also be beneficial to address the trauma and rebuild personal well-being.

Disclaimer: This is a general discussion of Philippine law related to marital infidelity. Legal outcomes depend on the specific facts of each case and may change with legislation or court decisions. Always consult a qualified attorney for advice tailored to your individual situation.