Introduction

In the Philippine legal system, marital infidelity is not merely a moral or social issue but can constitute criminal offenses under the Revised Penal Code (RPC). While adultery pertains to the infidelity of a married woman, concubinage addresses the infidelity of a married man, potentially implicating his mistress in criminal liability. This article explores the criminal responsibility of a husband's mistress, focusing on the provisions of Philippine law, the elements required for conviction, penalties, procedural aspects, and related legal frameworks. The discussion is grounded in the Philippine context, where family values and Catholic influences shape legal norms, yet the law provides specific remedies for aggrieved spouses.

The concept of a "mistress" in this context refers to a woman who engages in a sexual or cohabitative relationship with a married man, knowing or having reason to know of his marital status. Criminal liability arises not from the relationship per se but from meeting the statutory elements of concubinage. This offense reflects the patriarchal origins of the RPC, inherited from Spanish colonial law, which treats male and female infidelity differently—adultery being easier to prove and harsher in penalty than concubinage.

Legal Basis: Article 334 of the Revised Penal Code

The primary legal foundation for the criminal liability of a husband's mistress is Article 334 of the RPC, as amended. This provision defines concubinage as follows:

"Any husband who shall keep a mistress in the conjugal dwelling, or shall have sexual intercourse, under scandalous circumstances, with a woman who is not his wife, or shall cohabit with her in any other place, shall be punished by prision correccional in its minimum and medium periods.

The concubine shall suffer the penalty of destierro."

Enacted in 1930 and based on the Spanish Penal Code of 1870, this article criminalizes three distinct modes of commission by the husband:

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

The mistress, referred to as the "concubine," is held liable as a co-principal if she participates knowingly in any of these acts. Unlike adultery, where the paramour is liable regardless of knowledge, concubinage requires proof that the mistress was aware of the man's marriage. This knowledge can be inferred from circumstances, such as the man's wearing of a wedding ring, references to his family, or public knowledge of his marital status.

The RPC's gender-specific treatment has been criticized for inequality, as concubinage is harder to prove than adultery (which requires only one act of intercourse). Efforts to reform this, such as proposals for a gender-neutral infidelity law, have not yet succeeded as of the latest legislative sessions.

Elements of Concubinage Involving the Mistress

For the mistress to be criminally liable, the prosecution must establish the following elements beyond reasonable doubt:

The offender is a married man: The husband must be legally married at the time of the offense. Annulment or legal separation does not retroactively absolve liability if the acts occurred during the marriage.
Commission of one of the three acts:
- Keeping a mistress in the conjugal dwelling: This involves maintaining the woman in the family home with the character of a concubine, implying ongoing sexual relations and support. Isolated visits do not suffice; there must be a semblance of permanence.
- Sexual intercourse under scandalous circumstances: "Scandalous" implies public notoriety or offense to decency, such as acts in public places, hotels known for illicit affairs, or situations causing public outrage. Discreet encounters in private do not qualify.
- Cohabitation in any other place: This means living together as husband and wife without legal marriage, involving sexual intimacy and shared residence. It need not be continuous but must show a pattern of cohabitation.
Knowledge of marital status by the mistress: The concubine must know or have constructive knowledge that the man is married. Ignorance can be a defense if proven, but courts often presume knowledge in long-term relationships.
The woman is not the legal wife: Self-evident, but bigamous marriages could complicate this if the mistress believes she is the "wife."

These elements must be proven through evidence like witness testimonies, hotel records, photographs, messages, or admissions. The burden is on the prosecution, and the accused enjoys the presumption of innocence under Article III, Section 14(2) of the 1987 Philippine Constitution.

Penalties and Sentencing

Upon conviction:

The husband faces prision correccional in its minimum and medium periods, ranging from 6 months and 1 day to 4 years and 2 months. This is an afflictive penalty that may include imprisonment.
The mistress is punished with destierro, a lighter penalty involving banishment from a specified place (usually the complainant's residence) for a period equal to the husband's sentence. Destierro does not involve imprisonment but restricts movement, typically for 2 years and 4 months to 6 years, depending on aggravating or mitigating circumstances.

Aggravating factors, such as the presence of children or public scandal, may increase penalties, while mitigating factors like voluntary surrender could reduce them. Under the Indeterminate Sentence Law (Act No. 4103, as amended), courts impose indeterminate sentences, allowing parole eligibility.

If the offense involves minors or coercion, additional liabilities under Republic Act (RA) No. 7610 (Child Protection Act) or RA No. 9262 (Anti-VAWC Act) may apply, escalating penalties.

Procedural Aspects: Filing, Prosecution, and Prescription

Who can file? Only the offended spouse (the wife) can initiate the complaint for concubinage. If she condones the act (e.g., through forgiveness or continued cohabitation), the case is barred. Both husband and mistress must be charged together; prosecuting one without the other is not allowed, as per jurisprudence (e.g., People v. Schneckenburger, G.R. No. L-48183).
Where to file? Complaints are filed with the Office of the City or Provincial Prosecutor, leading to preliminary investigation. If probable cause is found, an information is filed in the Regional Trial Court (RTC), as concubinage is under RTC jurisdiction.
Prescription period: The crime prescribes in 15 years from discovery (Article 90, RPC), reflecting its afflictive nature.
Pardon and condonation: The offended spouse's pardon extinguishes criminal liability, but it must be express and before the institution of the criminal action.

Defenses Available to the Mistress

Common defenses include:

Lack of knowledge: Proving genuine ignorance of the man's marriage.
Absence of elements: Arguing no cohabitation, no scandal, or no maintenance in the conjugal home.
Good faith: If the mistress believed the man was separated or divorced.
Constitutional challenges: Arguing gender inequality violates equal protection under the Constitution, though courts have upheld the distinction (e.g., Beltran v. People, G.R. No. L-31779).
Alibi or denial: Supported by evidence disproving involvement.

Related Laws and Overlapping Liabilities

While concubinage is the core offense, other laws may intersect:

Family Code (Executive Order No. 209): Articles 35-55 govern marriage validity. A mistress in a bigamous setup could face bigamy charges (Article 349, RPC) if she marries the man knowing his prior marriage.
RA No. 9262 (Anti-Violence Against Women and Their Children Act of 2004): Psychological violence from infidelity can lead to civil or criminal actions against the husband, but the mistress may be liable as an accomplice if she aids in abuse.
RA No. 10175 (Cybercrime Prevention Act of 2012): If the affair involves online solicitation or explicit content, additional charges like cyber-libel or child pornography could apply if minors are involved.
Civil liabilities: The mistress may face damages in a civil suit for alienation of affection or under Article 26 of the Family Code for meddling in family relations.
RA No. 9995 (Anti-Photo and Video Voyeurism Act): Relevant if intimate media is shared without consent.

In indigenous or Muslim communities, customary laws under the Indigenous Peoples' Rights Act (RA 8371) or the Code of Muslim Personal Laws (Presidential Decree 1083) may provide alternative resolutions, but RPC prevails in criminal matters.

Jurisprudence: Key Supreme Court Decisions

Philippine courts have clarified concubinage through rulings:

People v. Pitoc (G.R. No. L-5238, 1953): Cohabitation requires more than occasional meetings; it implies living together as spouses.
U.S. v. Arlante (9 Phil. 326, 1907): Scandalous circumstances involve acts offending public morals.
Ligtas v. Court of Appeals (G.R. No. L-56712, 1983): Knowledge can be presumed from circumstantial evidence.
Serrano v. People (G.R. No. 175023, 2010): Reiterated that both parties must be prosecuted jointly.
Recent cases (post-2020) under RA 9262 often link concubinage to economic abuse, allowing protective orders against the mistress.

These decisions emphasize strict proof requirements, leading to low conviction rates for concubinage compared to adultery.

Challenges and Reforms

Critics argue the law's gender bias perpetuates inequality, with women's groups advocating repeal or amendment. Bills like the proposed "Infidelity Act" seek uniform penalties. Enforcement is hampered by evidentiary difficulties, cultural stigma against filing, and the private nature of affairs. In practice, many cases settle via mediation or end in acquittal.

Conclusion

The criminal liability of a husband's mistress under Philippine law centers on concubinage, a relic of colonial jurisprudence that imposes lighter penalties on women involved in male infidelity. While providing recourse to aggrieved wives, it requires rigorous proof and faces calls for modernization. Understanding this framework is crucial for legal practitioners, as it intersects with family, civil, and human rights laws, underscoring the tension between tradition and equality in Philippine society. Individuals facing such issues should consult qualified counsel for case-specific advice.