In the Philippines, marriage is a special contract and a social institution protected by the 1987 Constitution and reinforced by statute. Infidelity undermines the marital bond and triggers both criminal and civil liabilities. The Revised Penal Code (Act No. 3815, as amended) defines and penalizes two specific offenses—adultery and concubinage—while the Family Code of 1987 (Executive Order No. 209) supplies the principal civil remedies of legal separation, support, property liquidation, and, in limited circumstances, evidence for declaration of nullity of marriage. These laws apply uniformly to all marriages solemnized under the Civil Code or Family Code; Muslim personal law under Presidential Decree No. 1083 governs only persons who have elected to be subject to it and is outside the scope of the general regime discussed here.

Criminal Liabilities: Adultery (Article 333, Revised Penal Code)

Adultery is committed by any married woman who shall have sexual intercourse with any man not her husband and by the man who has carnal knowledge of her, knowing her to be married.

Essential elements

The woman is legally married at the time of the sexual act.
She has sexual intercourse with a man who is not her lawful husband.
The man knows that she is married.

Only one act of sexual intercourse is required; there is no need to prove scandal, cohabitation, or repetition. Both the wife and the paramour are principals in the crime. The offended party—the husband—is the sole person authorized to file the complaint.

Penalty
Prision correccional in its medium and maximum periods (two years, four months and one day to six years). Accessory penalties include temporary absolute disqualification and suspension from public office.

Criminal Liabilities: Concubinage (Article 334, Revised Penal Code)

Concubinage is committed by any husband who shall (a) keep a mistress in the conjugal dwelling, (b) have sexual intercourse with a woman who is not his wife under scandalous circumstances, or (c) cohabit with such woman in any other place. The concubine is likewise liable.

Essential elements according to mode

Keeping a mistress in the conjugal dwelling: the woman must reside in the family home in the character of a mistress.
Sexual intercourse under scandalous circumstances: the act must be public or notorious.
Cohabitation: the husband and the woman live together as husband and wife in any place other than the conjugal dwelling.

The husband is punished as principal; the concubine is punished with destierro (banishment from 6 months and 1 day to 6 years). The same penalty of prision correccional in its medium and maximum periods applies to the husband.

Distinctions Between Adultery and Concubinage

Adultery penalizes the wife and her paramour on the basis of a single sexual act; concubinage requires either scandal, cohabitation, or the maintenance of a mistress in the family home. The law thus imposes a higher threshold for criminal liability on the husband. Both offenses are private crimes under Article 344 of the Revised Penal Code: they cannot be prosecuted de officio by the state or by any relative except the offended spouse. The complaint must name both guilty parties if they are alive; a complaint against only one is defective.

Procedure for Criminal Prosecution

The offended spouse executes a sworn complaint-affidavit detailing the acts and supporting evidence.
The complaint is filed with the prosecutor’s office having jurisdiction over the place where the offense was committed or where the offended spouse resides.
After preliminary investigation, an information is filed with the Regional Trial Court.
The case proceeds as an ordinary criminal action. Bail is ordinarily available.

Conviction carries civil liability ex delicto, allowing the court to award moral damages, exemplary damages, and attorney’s fees without a separate civil filing.

Defenses and Extinguishment of Criminal Liability

Express pardon: A written or oral forgiveness given before or after the filing of the complaint extinguishes liability.
Implied pardon: Cohabitation or resumption of marital relations after the offended spouse acquires knowledge of the infidelity.
Lack of knowledge (available only to the paramour in adultery).
Death of the offended spouse before the filing of the complaint.

Once pardon is granted, whether express or implied, the criminal action cannot be revived for the same act even if infidelity recurs, unless a new and separate offense is committed.

Civil Remedy: Legal Separation (Articles 55 and 63, Family Code)

Sexual infidelity or perversion is an independent ground for legal separation. Proof of the acts constituting adultery or concubinage is sufficient; a prior criminal conviction is not required. The standard of proof is preponderance of evidence.

Effects of the decree of legal separation

Spouses are entitled to live separately.
The absolute community or conjugal partnership is dissolved and liquidated.
The offending spouse forfeits his or her share in the net profits of the property regime.
The offending spouse is disqualified from inheriting from the innocent spouse by intestate succession and from receiving support unless the court rules otherwise for compelling reasons.
Custody of minor children is awarded according to the best interest of the child; the guilty spouse’s infidelity may be weighed as a factor affecting parental fitness.
The innocent spouse and children retain the right to support from the guilty spouse’s separate property or earnings.

The marriage bond is not dissolved; neither party may remarry. Reconciliation before the decree becomes final allows the court to set aside the decree.

Declaration of Nullity of Marriage (Article 36, Family Code)

Infidelity per se is neither a ground for annulment of a voidable marriage nor for declaration of nullity. However, in a petition under Article 36, chronic or compulsive infidelity may be introduced as circumstantial evidence of psychological incapacity to comply with the essential marital obligations of fidelity, mutual love, and respect, provided the incapacity is shown to be: (a) grave, (b) juridically antecedent to the marriage, and (c) incurable or permanent. Standing alone, even repeated acts of infidelity are insufficient.

Additional Civil Remedies and Consequences

Moral and exemplary damages: Recoverable in the criminal case or in a separate civil action. The third party (paramour or concubine) may be held solidarily liable when the evidence establishes bad faith or malicious interference.
Forfeiture and disqualification: In legal separation, the guilty spouse loses the right to manage the conjugal property and is disqualified from inheriting.
Support and property rights: Temporary support pendente lite may be ordered during any proceeding. Upon liquidation, the innocent spouse is entitled to one-half of the net conjugal assets plus any forfeiture imposed on the guilty spouse.
Child-related orders: Child support is mandatory; custody follows the best-interest rule. Visitation rights of the guilty parent are protected unless contrary to the child’s welfare.

Philippine law does not recognize the common-law tort of “alienation of affection.” No independent civil action lies against the third party solely for causing the infidelity.

Practical Considerations in Enforcement

Evidence commonly accepted includes witness testimony, photographs, text messages, hotel records, DNA results, and admissions. Because adultery and concubinage are private crimes, the offended spouse retains absolute control over whether to prosecute criminally or pursue only civil relief. Many spouses elect legal separation alone to avoid the social stigma of a criminal trial while securing property and support rights. Reconciliation remains a policy favored by the Family Code; courts routinely suspend proceedings to allow mediation.

These statutory provisions—rooted in the Revised Penal Code and the Family Code—continue to govern all legal remedies available to an aggrieved spouse in cases of marital infidelity in the Philippines.