Introduction

In the Philippines, adultery remains a criminal offense under the Revised Penal Code (RPC), reflecting the country's strong emphasis on family values and marital fidelity as enshrined in the 1987 Constitution and various civil laws. While the RPC primarily adheres to the principle of territoriality in criminal jurisdiction, certain personal crimes, including those affecting marital relations, may extend beyond the nation's borders. This article explores the criminal liability for adultery committed abroad by Filipino citizens, the jurisdictional reach of Philippine courts, relevant legal provisions, jurisprudential interpretations, and practical implications. It delves into the interplay between criminal law, family law, and principles of nationality, providing a comprehensive analysis within the Philippine legal framework.

Definition and Elements of Adultery Under Philippine Law

Adultery is defined and penalized under Article 333 of the RPC, which states: "Adultery is 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 prision correccional in its medium and maximum periods (ranging from 2 years, 4 months, and 1 day to 6 years).

The elements of adultery are:

The offender is a married woman.
She engages in sexual intercourse with a man who is not her husband.
The man knows that she is married.

Notably, adultery is gender-specific under the RPC, applying only to married women and their paramours. This asymmetry has been criticized as discriminatory, but it remains the law unless amended or declared unconstitutional. The corresponding crime for married men is concubinage under Article 334, which requires additional elements like cohabitation or scandalous circumstances and carries lighter penalties.

Adultery is classified as a private crime under Article 344 of the RPC, meaning it can only be prosecuted upon complaint by the offended spouse. Pardon or consent by the offended party extinguishes criminal liability. This private nature underscores its focus on personal marital harm rather than public order.

The Principle of Territoriality in Philippine Criminal Law

Philippine criminal law generally follows the territoriality principle, as articulated in Article 2 of the RPC: "Except as provided in the treaties and laws of preferential application, the provisions of this Code shall be enforced not only within the Philippine Archipelago, including its atmosphere, its interior waters and maritime zone, but also outside of its jurisdiction, against those who: [enumerated exceptions]."

Under this principle, crimes committed outside Philippine territory are not punishable unless they fall under specific exceptions, such as:

Offenses committed by public officers in the exercise of their functions.
Crimes against national security (e.g., treason, espionage).
Forgery of Philippine currency or government securities.
Acts on Philippine ships or aircraft.
Crimes that produce effects within the Philippines.

Adultery does not inherently fit these exceptions, as it is a personal crime without direct impact on national security or public institutions. Thus, at first glance, adultery committed abroad might seem beyond the reach of Philippine courts.

Extraterritorial Application: The Nationality Principle and Family Law

Despite the territoriality rule, Philippine law incorporates the nationality principle for certain matters, particularly those involving personal status and family relations. Article 15 of the Civil Code provides: "Laws relating to family rights and duties, or to the status, condition and legal capacity of persons are binding upon citizens of the Philippines, even though living abroad."

This provision extends the application of Philippine laws on marriage and family to Filipino citizens worldwide. Marriage, being a social institution protected by the State (Article II, Section 12 of the 1987 Constitution), carries obligations that transcend borders. Crimes that undermine marital fidelity, such as adultery, are seen as violations of these personal laws.

The rationale is rooted in the concept of lex personalis or personal law, where a citizen's status follows them regardless of location. This is analogous to bigamy under Article 349 of the RPC, which Philippine courts have consistently held to be punishable even if committed abroad by a Filipino, as marriage validity is governed by national law (e.g., People v. De Guzman, G.R. No. L-16443, 1961).

For adultery, the extension is justified because it directly affects the marital bond, which is governed by Philippine law for Filipinos. If both parties are Filipinos, or if the offender is a Filipino married under Philippine law, the crime's commission abroad does not bar prosecution, provided jurisdiction can be established.

Jurisprudential Interpretations and Case Law

Philippine jurisprudence has affirmed the extraterritorial application of adultery laws in specific contexts. Key cases include:

People v. Tria (G.R. No. L-14595, March 29, 1960): The Supreme Court ruled that a Filipino wife who committed adultery in Japan with a non-Filipino could be prosecuted in the Philippines. The Court emphasized that Article 15 of the Civil Code binds Filipinos to family laws abroad, and adultery, as a crime against marital status, falls under this purview. The decision highlighted that the offended husband's Filipino citizenship and the marriage's celebration under Philippine law suffice for jurisdiction.
People v. Perez (G.R. No. L-21049, December 22, 1966): This case involved concubinage (the male equivalent) committed abroad. While not directly on adultery, the Court analogized it to adultery, stating that crimes against chastity and marital relations are personal and follow the nationality of the offender. The ruling reinforced that Philippine courts have jurisdiction over such offenses by Filipinos overseas.
Van Dorn v. Romillo (G.R. No. L-68470, October 8, 1985): Although a civil case on divorce, it underscored that Philippine laws on marriage apply to Filipinos abroad, influencing criminal interpretations. The Court noted that aliens may not invoke Philippine laws against Filipinos in marital disputes, but Filipinos remain bound.

However, limitations exist:

If the adulterous act involves a non-Filipino spouse or occurs in a jurisdiction where adultery is not criminalized, conflicts of law may arise. Under Article 14 of the RPC, penal laws have no retroactive effect, and foreign judgments may be considered under principles of comity.
Jurisdiction requires the offender's presence in the Philippines or extradition. The Philippines has extradition treaties (e.g., with the US under PD 1069), but adultery may not qualify as an extraditable offense unless specified.
In Imbong v. Ochoa (G.R. No. 204819, April 8, 2014), the Reproductive Health Law case indirectly touched on family rights, reaffirming State protection of marriage but not altering adultery's criminal status.

Recent discussions in Congress (e.g., bills to decriminalize adultery) have not yet resulted in amendments, so the law stands.

Procedural Aspects and Evidence

Prosecution for adultery committed abroad requires:

A complaint from the offended spouse (Article 344, RPC).
Proof of the elements, often challenging due to extraterritoriality. Evidence may include witness testimonies, admissions, or digital records. The Rules of Court allow affidavits from abroad, authenticated via consular channels.
Venue: Filed where the offended party resides (Rule 110, Section 15, Rules of Court).
Prescription: Eight years from discovery (Article 90, RPC), which may start upon return to the Philippines.

Defenses include lack of knowledge of marriage, absence of sexual intercourse, or pardon by the spouse. Insanity or other exempting circumstances under Article 12 apply universally.

Implications for Overseas Filipino Workers (OFWs) and Dual Citizens

With millions of OFWs, this topic has practical relevance. Filipino women working abroad risk criminal liability for extramarital affairs, even if culturally accepted in host countries. Dual citizens may face dual jeopardy if adultery is criminalized abroad (e.g., in Islamic nations), but the Philippines does not recognize double jeopardy for foreign convictions unless under treaty.

The law's gender bias has drawn criticism from human rights groups, arguing it violates equality under Article III, Section 1 of the Constitution. Proposals for gender-neutral infidelity laws persist, but no changes have occurred.

Conclusion

Adultery committed abroad by Filipino citizens falls under Philippine criminal jurisdiction through the nationality principle in family law, overriding strict territoriality. Supported by the RPC, Civil Code, and jurisprudence, this ensures marital obligations bind Filipinos globally. However, enforcement challenges, evidentiary hurdles, and evolving societal norms highlight the need for potential reforms. Until then, awareness of these provisions is crucial for preserving family integrity amid globalization.