In Philippine law, a wife who discovers her husband’s extramarital affair with a mistress (commonly referred to as a “concubine” in legal parlance) has specific criminal and civil remedies available. The legal framework is rooted in the Revised Penal Code (RPC) for criminal liability and the Family Code of the Philippines for civil consequences. These remedies reflect the country’s strong emphasis on the sanctity of marriage under the 1987 Constitution and prevailing Catholic-influenced civil law traditions, where absolute divorce remains unavailable to non-Muslim Filipinos.

I. Criminal Liability: Concubinage under the Revised Penal Code

The primary criminal offense applicable when a husband maintains a mistress is concubinage, defined and penalized under Article 334 of the Revised Penal Code (Act No. 3815, as amended).

Elements of Concubinage

The crime is committed by the husband in any of the following ways:

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

The mistress (concubine) is equally liable as a co-principal if she knows the man is married. The law does not require proof of actual sexual intercourse in the first mode (keeping in the conjugal dwelling), as the mere fact of maintaining the mistress there is sufficient. In the second and third modes, scandalous circumstances or cohabitation must be established.

Concubinage is a private crime under Article 344 of the RPC. Only the offended spouse—the wife—may file the complaint. The husband cannot be prosecuted for concubinage by any other person, including the State or the mistress’s relatives. The complaint must be filed by the wife herself or through a special power of attorney executed by her.

Penalty

Concubinage is punishable by prision correccional in its minimum and medium periods (from six (6) months and one (1) day to four (4) years and two (2) months). The same penalty applies to the concubine. The penalty is the same regardless of which mode is committed.

Prescription and Procedural Requirements

The action prescribes in one (1) year from the time the offended spouse had knowledge of the offense (Article 90, RPC, as modified by Act No. 3763). The complaint must be filed before a prosecutor’s office or directly with the Metropolitan Trial Court/Municipal Trial Court having jurisdiction over the place where the offense was committed or where the offended party resides.

Evidence typically includes:

A certified true copy of the marriage certificate;
Proof of the husband’s relationship with the mistress (photographs, videos, affidavits of witnesses, hotel records, lease contracts, or social media evidence showing cohabitation or scandalous conduct);
Birth certificates of children born from the illicit relationship (if any), which may serve as corroborative evidence.

Philippine courts have consistently held that mere suspicion is insufficient; the evidence must establish the elements beyond reasonable doubt. However, direct proof of sexual intercourse is not always necessary if the first or third mode is alleged.

Distinction from Adultery

It is important to note that adultery (Article 333, RPC) applies only when a married woman has sexual relations with a man not her husband. The husband cannot be charged with adultery; only concubinage applies to him. This gender asymmetry has been criticized but remains the law unless repealed by Congress.

II. Civil Remedies under the Family Code

A criminal case for concubinage does not preclude the filing of a separate civil action for legal separation. In fact, the two are often pursued simultaneously.

Legal Separation (Articles 55–67, Family Code)

Grounds: Article 55(8) and (9) expressly include “concubinage” and “attempted or consummated adultery” as grounds for legal separation. The wife may file a petition for legal separation on the ground of her husband’s concubinage.

Prescriptive Period: The petition must be filed within five (5) years from the time the cause of action accrued (i.e., from the time the wife discovered the concubinage).

Effects of Legal Separation (Article 63):

The spouses are entitled to live separately.
The offending spouse (husband) forfeits his share of the net profits of the conjugal partnership or absolute community property.
The custody of minor children is awarded to the innocent spouse (subject to the best-interest-of-the-child rule).
The offending spouse is disqualified from inheriting from the innocent spouse by intestate succession.
The innocent spouse may revoke donations made in favor of the offending spouse.
Separation of property is effected.

Reconciliation is encouraged; the Family Code allows resumption of marital relations, which automatically terminates the legal separation decree.

Annulment or Declaration of Nullity

Infidelity alone is not a ground for annulment of marriage or declaration of nullity. However:

If the husband’s infidelity is so severe that it demonstrates psychological incapacity (Article 36, Family Code) existing at the time of the marriage and rendering him unable to fulfill essential marital obligations, a nullity petition may be filed.
Fraud under Article 46 (concealment of a previous criminal conviction, drug addiction, habitual alcoholism, or homosexuality) does not include post-marriage infidelity.
Bigamy (Article 41, Family Code and Article 349, RPC) applies if the husband contracts a second marriage while the first subsists.

Support and Property Rights

Pending legal separation or nullity proceedings, the wife may seek support pendente lite (Article 49, Family Code) and spousal support under the Revised Penal Code (as civil liability arising from the crime). Conjugal property may be placed under administration by the innocent spouse.

Damages

In the criminal case for concubinage, the wife may claim moral damages (Article 2219, Civil Code) for the mental anguish, besmirched reputation, and social humiliation caused by the affair. Actual damages (e.g., medical expenses for stress-related illness) and exemplary damages may also be awarded.

III. Other Related Offenses and Remedies

Bigamy – If the husband marries the mistress while the first marriage is subsisting, both the husband and the mistress (if she knows of the existing marriage) may be prosecuted for bigamy (Article 349, RPC), punishable by prision mayor.
Violence Against Women and Children (RA 9262) – If the husband’s infidelity is accompanied by physical, emotional, psychological, or economic abuse, the wife may file under the Anti-VAWC law. Emotional and psychological violence expressly includes marital infidelity that causes mental or emotional suffering.
RA 9995 (Anti-Photo and Video Voyeurism Act) and RA 10175 (Cybercrime Prevention Act) – May apply if the affair involves non-consensual sharing of intimate images or online harassment.
Child Custody and Support – Illegitimate children born to the mistress are entitled to support from the father (Article 194, Family Code), but the wife retains priority in legitimate children’s custody.

IV. Practical and Procedural Considerations

Venue and Jurisdiction:

Criminal: Where the offense was committed or where the offended party resides.
Civil: Regional Trial Court of the place where the spouses reside or where the marriage was celebrated.

Evidence Rules:

Illegally obtained evidence (e.g., hacked emails or recordings) may be inadmissible under the fruit-of-the-poisonous-tree doctrine and the right to privacy.
Witness testimony from household helpers, neighbors, or private investigators is commonly used and accepted if credible.

Double Jeopardy and Lis Pendens: A criminal acquittal does not bar a civil petition for legal separation, as the quantum of proof differs (beyond reasonable doubt vs. preponderance of evidence).

Current Legal Landscape: As of the latest statutory framework, concubinage and adultery remain criminal offenses. Legislative proposals to decriminalize these “private crimes” have been filed in Congress, citing gender inequality and modern realities, but no repeal has been enacted. The Supreme Court has upheld the constitutionality of these provisions in various decisions, emphasizing the State’s interest in protecting marriage.

Muslim Personal Laws: For Muslim Filipinos governed by Presidential Decree No. 1083 (Code of Muslim Personal Laws), divorce (talaq, faskh) is recognized, and concubinage provisions under the RPC may be supplemented or superseded by Shari’ah court proceedings.

In summary, Philippine law provides the aggrieved wife with robust criminal and civil remedies against both the unfaithful husband and his mistress. The choice of remedy—criminal concubinage, legal separation, or both—depends on the wife’s objectives: punishment, property separation, custody, or moral vindication. Success hinges on meticulous documentation and timely filing within the respective prescriptive periods.