Adultery Laws in the Philippines for Unmarried Couples
(A comprehensive legal discussion in the Philippine context)

1. Overview of Adultery and Concubinage Under Philippine Law

Under Philippine law, adultery and concubinage are criminal offenses punishable under the Revised Penal Code (RPC). Although both crimes involve marital infidelity, they each address different circumstances:

Adultery (Article 333 of the Revised Penal Code) – This crime is committed by a married woman who engages in sexual intercourse with a man who is not her husband, and by the man who has carnal knowledge of her if he knows her to be married.
Concubinage (Article 334 of the Revised Penal Code) – This crime is committed by a married man under certain specific circumstances (e.g., keeping a mistress, cohabiting with her, or habitually engaging in sexual intercourse under scandalous circumstances), and by the mistress or concubine, if she is aware of his marital status.

Crucially, both adultery and concubinage require that at least one of the parties be legally married. Where neither party is married, these offenses generally do not apply.

2. Adultery and Its Elements

Article 333 (Adultery) of the Revised Penal Code provides:

There must be sexual intercourse.
The woman is legally married to someone else at the time of the act.
The man involved knows that the woman is married.

For adultery to stand in court, each act of intercourse constitutes one count of adultery. This differs from concubinage, which usually treats the arrangement as one continuing crime.

Key Points to Remember:

Only a married woman can commit adultery.
An unmarried man commits adultery if he has carnal knowledge of a woman knowing she is married.
If a man is unmarried, the law will not consider his relationship with an unmarried woman as adultery, because both parties must involve at least one married individual for it to fall under adultery or concubinage.

3. What If Both Parties Are Unmarried?

If both parties are unmarried, the offense of adultery (or concubinage) does not arise because the Revised Penal Code provisions apply specifically to marital infidelity—that is, to protect the sanctity of marriage. If neither party has a subsisting marriage bond, there is no spouse whose rights are being violated in the legal sense contemplated by Articles 333 and 334 of the Revised Penal Code.

Example: Two unmarried individuals cohabiting or engaging in a sexual relationship. Since there is no marriage, there is no “spouse” being betrayed. Legally, there is no crime of adultery or concubinage in such a scenario.

4. When One Party Is Unmarried But the Other Is Married

To clarify the scope regarding “unmarried couples” within the broader context of marital infidelity:

Married Woman + Unmarried Man
- This scenario can give rise to the crime of adultery, provided the unmarried man knows that the woman is married.
- The married woman who engages in such a relationship is also liable for adultery.
Married Man + Unmarried Woman
- This scenario can fall under concubinage if the relationship meets the specific conditions under Article 334 of the RPC. Merely having sexual relations with a married man is not automatically concubinage; the law specifies more stringent conditions (e.g., cohabitation under scandalous circumstances, keeping a mistress in the conjugal dwelling, etc.).
- That said, an unmarried woman who continues to cohabit with a married man—knowing he is married—can also be liable under concubinage, if the facts so warrant.

Hence, when people discuss “unmarried couples” in the context of adultery, it typically means the man (unmarried) and the woman (married). The unmarried man’s knowledge of her being married is critical for the offense to be considered adultery.

5. Legal Implications if Both Are Unmarried but One Has a Pending Marriage Annulment or Separation

Sometimes, complicated situations arise if one party has a pending annulment or is merely physically separated from a spouse but not legally recognized as single. Under Philippine law:

Annulment Not Yet Final: A marriage is deemed subsisting until a court issues a final judgment of annulment or nullity. If a woman’s marriage has not been formally declared null or void, she is still considered legally married. Hence, sexual relations with another man may be deemed adultery.
Judicial Declaration of Nullity: For a marriage to be officially null, there must be a court declaration. Simply believing that one’s marriage is void or acting on an informal separation is insufficient. If no official court declaration exists, the law presumes the marriage to be valid.

6. Remedies and Legal Action

Filing a Criminal Complaint
- Only the offended spouse can file for adultery (or concubinage); the State will not initiate the complaint on its own.
- For adultery, a husband who believes his wife has been unfaithful may file a criminal complaint against both his wife and her partner.
- The complaint must be filed against both parties (the wife and her alleged lover), or the case is subject to dismissal.
Proof and Evidence
- Proof of actual sexual intercourse is required. In practice, due to privacy considerations, direct evidence (e.g., eyewitness testimony of the actual act) is rarely available.
- Courts typically rely on indirect or “circumstantial” evidence, such as hotel receipts, correspondence, incriminating photographs, or other forms of physical or digital evidence that strongly suggest an adulterous relationship.
- Each act of intercourse can be charged as a separate count of adultery if sufficiently proven.
Defense Considerations
- Denial of knowledge of the woman’s marital status may be raised by the unmarried man. But if there is reasonable indication he was aware (e.g., introduced to or aware of her existing spouse), the defense can fail.
- Showing that the marriage was already annulled or void at the time of the alleged offense could be a defense. However, an ongoing but incomplete annulment process is not a valid defense if the marriage had not yet been judicially voided.

7. Penalties

Under the Revised Penal Code:

Adultery (Article 333): Penalty of prisión correccional in its medium and maximum periods (i.e., from 2 years, 4 months, and 1 day to 6 years).
Concubinage (Article 334): Penalty of prisión correccional in its minimum and medium periods (6 months and 1 day to 4 years and 2 months) for the husband, and a lesser penalty of destierro (banishment from a specified radius) for the concubine.

Because the prescribed penalties involve imprisonment, these are criminal cases of a serious nature. However, actual prison time can depend on many factors (e.g., plea bargaining, mitigating circumstances, etc.).

8. Civil and Other Consequences

Nullity of Marriage or Legal Separation: Proof of adultery or concubinage can be grounds for a petition for legal separation, and in certain cases, used as evidence of marital misconduct in petitions for nullity or annulment (though the specific grounds vary).
Psychological Incapacity Cases: While not directly related to adultery laws, marital infidelity can sometimes be invoked as indicative of certain behaviors in nullity cases under Article 36 of the Family Code (psychological incapacity).
Damages: The offended spouse may seek moral damages and other forms of civil relief, though in practice this often accompanies the criminal action or a separate civil suit.

9. Related Legal Considerations

Violence Against Women and Children (RA 9262): If the circumstances lead to harassment, abuse, or economic deprivation, the offended spouse (usually the wife) may consider filing a complaint under the Anti-Violence Against Women and Their Children Act.
Cyber Adultery or Electronic Evidence: While “cyber adultery” is not a separate crime under the RPC, electronic communications (text messages, emails, social media exchanges) can be used as evidence in adultery or concubinage cases if properly obtained and authenticated.
Privacy Laws: In gathering proof, one must remain mindful of the Anti-Wiretapping Act (RA 4200) and Data Privacy Act (RA 10173). Illegally obtained evidence may be inadmissible in court.

10. Frequently Asked Questions (FAQs)

Q1: Can I be charged with adultery if I’m unmarried and my partner is also unmarried?
A1: No. Adultery applies only when the woman is married. If both are unmarried, there is no crime of adultery or concubinage under the Revised Penal Code.

Q2: Can I claim ignorance of her marital status as a defense?
A2: Yes. If you sincerely did not know that the woman was married—and the prosecution cannot prove otherwise—ignorance may serve as a valid defense. However, the court will examine whether there were indicators that you reasonably should have known.

Q3: Does de facto separation exempt a woman from being charged with adultery?
A3: No. Regardless of physical separation or informal agreements, if there has been no final court declaration of nullity or annulment, the marriage still legally exists.

Q4: Is it necessary for the offended spouse to charge both the spouse and the third party?
A4: Yes. In adultery cases, the complainant must file the case against both alleged offenders (the spouse and the spouse’s partner). Failing to do so can result in the dismissal of the complaint.

Q5: Could cohabiting unmarried partners be criminally liable for any other offense?
A5: Generally, no—unless other crimes arise (e.g., bigamy if one has a secret marriage, child abuse, or other criminal acts). Simply living together as unmarried partners, where no one is legally married, is not a criminal offense in Philippine law.

11. Practical Tips and Concluding Notes

For unmarried couples, the primary takeaway is that adultery or concubinage does not apply unless one party is legally married.
If you are entering a relationship with someone who claims to be separated or in the process of annulment, it is prudent to confirm the legal status of that person’s marriage to avoid legal entanglements.
If you are an offended spouse considering a complaint, consult a qualified lawyer to understand the evidence requirements and the potential outcomes.
Philippine law strongly protects marital rights under criminal statutes, so any allegation of infidelity can have serious legal consequences—including imprisonment—if proved in court.

Disclaimer: This article is for general informational purposes only and does not constitute legal advice. Laws and their interpretations may change over time, and individual circumstances vary. For specific concerns, always seek the advice of a licensed Philippine attorney.