Introduction

In the Philippine legal system, adultery remains a criminal offense rooted in the country's colonial-era penal laws, reflecting a strong emphasis on the sanctity of marriage as enshrined in the 1987 Constitution and the Family Code of the Philippines (Executive Order No. 209, as amended). Adultery, as a ground for both criminal prosecution and civil remedies, allows an aggrieved spouse to seek justice against the erring spouse and the third-party partner involved. This article explores the comprehensive legal framework governing such actions, including criminal liabilities, civil remedies, procedural requirements, defenses, and related jurisprudence. It is important to note that Philippine family law is influenced by Catholic traditions, making divorce unavailable except for Muslims under the Code of Muslim Personal Laws, and thus emphasizing legal separation or annulment as alternatives.

The Revised Penal Code (RPC) of 1930 (Act No. 3815, as amended) distinguishes between adultery (committed by a married woman) and concubinage (committed by a married man), creating an asymmetrical treatment that has been criticized for gender bias but remains in force. Legal actions in these cases aim to protect the institution of marriage, deter infidelity, and provide redress for emotional and moral harm. Spouses pursuing these actions must navigate both criminal and family courts, often requiring evidence of sexual acts or cohabitation.

Criminal Liability Under the Revised Penal Code

Adultery (Article 333, RPC)

Adultery is defined as a crime 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. The penalty is prisión correccional in its medium and maximum periods (2 years, 4 months, and 1 day to 6 years) for both the wife and her paramour.

Elements of the Crime:
1. The woman is married.
2. She engages in sexual intercourse with a man not her husband.
3. The man knows she is married.
Prosecution by the Aggrieved Spouse: Only the offended husband can initiate the criminal complaint for adultery. Under Article 344 of the RPC, the offended spouse must include both guilty parties (the wife and the paramour) in the complaint if both are alive. Failure to do so renders the prosecution invalid. The complaint must be filed with the prosecutor's office, leading to a preliminary investigation and potential indictment.
Prescription Period: The crime prescribes after 15 years from discovery (Article 90, RPC).

Concubinage (Article 334, RPC)

Concubinage applies to a married man and is committed in any of the following ways:

Keeping a mistress in the conjugal dwelling.
Having sexual intercourse under scandalous circumstances with a woman not his wife.
Cohabiting with her in any other place.

The penalty is lighter: prisión correccional in its minimum and medium periods (6 months and 1 day to 4 years and 2 months) for the husband, and destierro (banishment) for the concubine.

Elements of the Crime:
1. The man is married.
2. He commits one of the acts described above.
3. The woman knows he is married (for her liability).
Prosecution by the Aggrieved Spouse: Similar to adultery, only the offended wife can file the complaint, and both the husband and the mistress must be included if alive. This ensures that the action is not used vindictively against one party.
Key Differences from Adultery: Concubinage requires proof of ongoing cohabitation or scandal, making it harder to prove than adultery, which only needs evidence of a single sexual act. This disparity has led to calls for reform, but no amendments have been made as of current law.

Procedural Aspects and Evidence

Filing the Complaint: The action begins with a sworn complaint-affidavit filed before the city or provincial prosecutor. Evidence may include witness testimonies, hotel records, photographs, messages, or admissions. Direct evidence of sexual intercourse is rare, so circumstantial evidence (e.g., opportunity and disposition) is often sufficient, as established in cases like People v. Zapata (G.R. No. L-30441, 1971).
Pardon and Consent (Article 344, RPC): The crime is extinguished if the offended spouse consents to the act or pardons the offenders, either expressly or impliedly (e.g., through continued cohabitation after discovery). Pardon must be given before the institution of the criminal action and applies to both parties.
Death of Parties: If the offended spouse dies before filing, the action cannot be pursued by heirs. If one guilty party dies, the case against the survivor may proceed only if the complaint was filed inclusively.
Jurisdiction: Criminal cases are heard in Regional Trial Courts (RTCs) with territorial jurisdiction over the place where the crime was committed.

Supreme Court rulings, such as People v. Santos (G.R. No. 98445, 1993), emphasize that the offended spouse's complaint is indispensable, underscoring the private nature of these offenses.

Civil Remedies Under the Family Code and Civil Code

Beyond criminal prosecution, adultery provides grounds for civil actions, allowing the aggrieved spouse to seek separation, support, custody, and damages.

Legal Separation (Articles 55-67, Family Code)

Adultery by the wife or concubinage by the husband is a ground for legal separation under Article 55(1) of the Family Code. Legal separation allows spouses to live apart without dissolving the marriage bond.

Requirements:
1. Filing a petition in the RTC.
2. Proof of the ground (adultery or concubinage).
3. Cooling-off period of six months after filing, during which reconciliation is encouraged.
Effects:
- Dissolution of the absolute community or conjugal partnership of gains.
- Custody of minor children typically awarded to the innocent spouse.
- The guilty spouse loses rights to net profits from community property and may be disqualified from succession.
- The innocent spouse may revoke donations made to the guilty spouse.
Defenses: Condonation (forgiveness), consent, connivance (encouragement of the act), mutual guilt, collusion, or prescription (5 years from discovery, Article 57).

In De la Viña v. Villareal (G.R. No. L-11612, 1918), the Court held that adultery must be proven by preponderance of evidence in civil cases, a lower threshold than beyond reasonable doubt in criminal proceedings.

Annulment or Declaration of Nullity

Adultery itself is not a ground for annulment (Article 45) or nullity (Article 36) of marriage. However, if infidelity stems from psychological incapacity (e.g., inability to fulfill marital obligations), it may support a petition for nullity under Article 36, as interpreted in Republic v. Molina (G.R. No. 108763, 1997). This requires expert psychological evidence.

Civil Damages (Articles 19-21, 26, and 32, Civil Code)

The aggrieved spouse can file a separate civil suit for damages against the erring spouse and the third party.

Moral Damages: For mental anguish, as in Alcantara v. Court of Appeals (G.R. No. 131547, 2001), where P500,000 was awarded for adultery causing emotional distress.
Exemplary Damages: To deter similar acts.
Nominal Damages: For vindication of rights.
Attorney's Fees and Costs.

The paramour can be held liable for tortious interference with marital relations under Article 26 (abuse of rights for meddling in family affairs).

Support and Property Division

During pendency of actions, the innocent spouse may seek spousal support (Article 194, Family Code) and child support. Property regimes are liquidated, with the guilty spouse potentially forfeiting shares.

Related Laws and Special Considerations

Republic Act No. 9262 (Anti-VAWC Act of 2004)

If adultery involves violence or economic abuse (e.g., abandoning the family), it may fall under RA 9262, allowing for protection orders, damages, and criminal penalties. Psychological violence includes causing mental harm through infidelity.

Republic Act No. 10175 (Cybercrime Prevention Act of 2012)

If evidence involves digital communications, adultery cases may intersect with cybercrimes like unauthorized access, but the primary action remains under the RPC.

Gender Considerations and Reform Efforts

The gender asymmetry in adultery and concubinage laws has been challenged as violative of equal protection under the Constitution (Article III, Section 1). In Estrada v. Escritor (A.M. No. P-02-1651, 2003), the Court discussed live-in relationships but upheld the laws. Legislative proposals, such as House Bill No. 2263 (Decriminalizing Adultery and Concubinage), aim to equalize penalties or decriminalize, but none have passed.

Impact on Children and Family

Courts prioritize the best interest of the child (Article 209, Family Code). Adultery cases can affect custody, with the guilty parent potentially losing it if it impairs child welfare.

Defenses and Limitations

Lack of Knowledge: The paramour is not liable if unaware of the marriage.
Invalid Marriage: If the marriage is void ab initio, no crime occurs.
Insanity or Duress: Rare defenses under general penal principles.
Amnesty or Pardon: Not applicable, as these are private crimes.

Jurisprudential Developments

Key cases include:

People v. Nepomuceno (G.R. No. L-40624, 1976): Circumstantial evidence suffices for conviction.
Ligtas v. Court of Appeals (G.R. No. 104154, 1994): Pardon must be unequivocal.
Santos v. Vda. de Caparas (G.R. No. 156503, 2006): Third-party liability for damages.

Conclusion

Legal actions for adultery in the Philippines provide aggrieved spouses with robust criminal and civil remedies to address infidelity, though the process is emotionally taxing and requires strong evidence. While the laws protect marital fidelity, their gender bias and rigidity highlight the need for modernization. Spouses considering such actions should consult licensed attorneys to navigate the complexities, ensuring compliance with procedural rules to avoid dismissal. Ultimately, these remedies underscore the Philippine legal system's commitment to family integrity amid evolving societal norms.