Introduction

In the Philippines, family law is governed primarily by the Family Code of the Philippines (Executive Order No. 209, as amended), the Revised Penal Code (Act No. 3815), and various special laws aimed at protecting marital relationships and family integrity. Infidelity within marriage is a sensitive issue that can lead to both criminal and civil liabilities. When a married individual engages in an extramarital affair, the aggrieved spouse may seek legal recourse not only against their erring partner but also against the third party involved, commonly referred to as the "mistress" in cases where the married partner is the husband. This article explores the various cases that can be filed against such a third party, focusing on criminal, civil, and administrative remedies available under Philippine law. It covers the legal bases, elements required for each action, procedural aspects, and potential defenses, providing a comprehensive overview within the Philippine legal context.

Criminal Liability: Concubinage Under the Revised Penal Code

The primary criminal case that can be filed against a married man's mistress is concubinage, as defined under Article 334 of the Revised Penal Code (RPC). This provision criminalizes the act of a husband keeping a mistress under specific circumstances, and the mistress herself can be held liable as a co-accused.

Elements of Concubinage

To establish concubinage, the following elements must be proven:

The offender is a married man: The husband must be legally married at the time of the offense.
He keeps a mistress: This can occur in one of three ways:
- Keeping the mistress in the conjugal dwelling (family home).
- Having sexual intercourse with her under scandalous circumstances (e.g., openly flaunting the relationship in a manner that causes public scandal).
- Cohabiting with her in any other place (living together as if husband and wife).
The mistress's involvement: The third party must knowingly participate in the relationship, aware of the man's marital status.

The penalty for the husband is prision correccional in its minimum and medium periods (6 months and 1 day to 4 years and 2 months), while the mistress faces destierro (banishment from a certain place for the same duration). Notably, concubinage is gender-specific under the RPC; it applies only to husbands and their female paramours. If the married partner is the wife, the equivalent crime against her paramour would be adultery (Article 333, RPC), which carries harsher penalties (prision correccional in its medium and maximum periods for both parties).

Filing the Complaint

Who can file? Only the offended spouse (the wife) can initiate the complaint, as concubinage is a private crime under Article 344 of the RPC. Pardon or consent from the offended spouse extinguishes the criminal liability.
Where to file? The complaint is filed with the Office of the City or Provincial Prosecutor for preliminary investigation, leading to potential indictment in the Regional Trial Court (RTC) if probable cause is found.
Prescription period: The crime prescribes in 15 years from discovery (Article 90, RPC).
Evidence required: Proof may include witness testimonies, photographs, messages, hotel records, or cohabitation evidence. Direct evidence of sexual intercourse is not always necessary if scandalous circumstances or cohabitation are established.

Defenses and Limitations

Common defenses include lack of knowledge of the man's marriage, absence of the required elements (e.g., no cohabitation or scandal), or proof that the marriage was void. However, the law's gender bias has been criticized, as adultery requires mere sexual intercourse for conviction, while concubinage demands more stringent proof. Attempts to challenge this disparity under equal protection clauses have not succeeded in fully repealing the provisions.

Other Criminal Remedies: Related Offenses

Beyond concubinage, additional criminal actions may be pursued if the mistress's conduct escalates to other violations:

Psychological Violence Under RA 9262 (Anti-VAWC Act)

Republic Act No. 9262, or the Anti-Violence Against Women and Their Children Act of 2004, allows for charges against a mistress if her actions cause mental or emotional anguish to the wife or children. This includes:

Public ridicule or humiliation related to the affair.
Threats or intimidation.
Infidelity itself as a form of psychological violence when it leads to marital breakdown.

The mistress can be charged as a principal or accomplice if she knowingly participates in acts that violate the law. Penalties range from fines to imprisonment, and a Protection Order (Barangay, Temporary, or Permanent) can be sought to restrain the mistress from contact. Cases are filed in the Family Court or RTC, with the offended party (woman or child) as the complainant.

Bigamy or Illegal Marriage (If Applicable)

If the mistress marries the husband without the prior marriage being annulled or dissolved, she may be liable for bigamy under Article 349 of the RPC, punishable by prision mayor (6 years and 1 day to 12 years). However, this requires proof of a subsequent valid marriage ceremony.

Other Penal Code Provisions

Unjust Vexation (Article 287, RPC): For minor annoyances or disturbances caused by the mistress, such as harassment.
Grave Scandal (Article 200, RPC): If the affair involves acts offensive to decency and good customs in public.

These are less common but can supplement primary charges.

Civil Remedies: Damages and Family Code Provisions

Civil actions provide avenues for monetary compensation and equitable relief without necessarily involving criminal prosecution.

Action for Damages Under Article 26 of the Family Code

Article 26 recognizes the right to damages for acts that alienate affections or interfere with marital relations, even if not criminal. The mistress can be sued for:

Moral damages (for emotional suffering).
Exemplary damages (to deter similar conduct).
Actual damages (e.g., counseling costs, lost income due to distress).

This is based on the principle of respecting the "dignity, personality, privacy, and peace of mind" of others. Cases are filed in the RTC, with a prescription period of 5 years from the act (Article 1146, Civil Code).

Legal Separation Under the Family Code

While primarily against the husband, the wife can cite concubinage as a ground for legal separation (Article 55), potentially implicating the mistress in related proceedings. The court may order support or property division, and the mistress could be subpoenaed as a witness.

Annulment or Nullity of Marriage

Infidelity alone is not a ground for annulment, but if fraud or psychological incapacity is linked to the affair, it may support such petitions. The mistress's role is indirect, but evidence of her involvement can strengthen the case.

Administrative and Ethical Considerations

If the mistress is a professional (e.g., lawyer, doctor), her conduct may violate ethical codes, leading to administrative complaints. For instance:

Under the Code of Professional Responsibility for lawyers, involvement in immoral conduct can result in disbarment.
Government employees may face charges under the Code of Conduct and Ethical Standards for Public Officials (RA 6713).

In custody battles, the affair can influence court decisions on child welfare under Article 211 of the Family Code.

Procedural Aspects and Practical Challenges

Burden of Proof

In criminal cases, proof beyond reasonable doubt is required; in civil cases, preponderance of evidence suffices. Gathering evidence often involves private investigators, digital forensics, or subpoenas for records.

Jurisdiction and Venue

Family-related cases are handled by Family Courts (RA 8369), while criminal matters go to RTCs. Venue is typically where the offense occurred or where the plaintiff resides.

Reconciliation and Settlement

Many cases end in amicable settlements, especially if the husband seeks reconciliation. Under Article 344, RPC, express pardon by the wife bars prosecution.

Societal and Cultural Context

Philippine society, influenced by Catholicism, views infidelity severely, but enforcement is uneven due to cultural stigma against publicizing family issues. Divorce is not legal (except for Muslims under PD 1083), making legal separation or annulment the primary marital dissolution options.

Conclusion

Navigating cases against a married partner's mistress requires a thorough understanding of both criminal and civil frameworks in the Philippines. Concubinage remains the cornerstone criminal action, supplemented by anti-violence laws and civil damages. Aggrieved parties should consult legal counsel to assess specific circumstances, as outcomes depend on evidence and judicial discretion. This legal landscape underscores the state's commitment to preserving family unity while providing remedies for breaches of marital fidelity.