In the Philippines, marriage is a special contract of permanent union between a man and a woman under Article 1 of the Family Code of the Philippines (Executive Order No. 209). Same-sex marriages are not recognized. When a husband engages in a same-sex extramarital affair, the legal consequences diverge sharply from those involving an opposite-sex affair, especially in criminal law, while civil remedies remain available to address the breach of marital obligations.

Criminal Liability

The Revised Penal Code provides two gender-specific crimes for marital infidelity:

Adultery (Article 333) is committed by a married woman who has sexual intercourse with a man not her husband, and by the man who has carnal knowledge of her knowing she is married.
Concubinage (Article 334) is committed by a married man who keeps a mistress in the conjugal dwelling, cohabits with her in another place under scandalous circumstances, or has sexual intercourse under scandalous circumstances. The term “mistress” refers exclusively to a woman.

Because the other party in the affair is male, neither adultery nor concubinage applies. No provision in the Revised Penal Code or any special law criminalizes consensual sexual relations between adults of the same sex. Consequently, no criminal complaint for adultery, concubinage, or any analogous offense can be filed against the husband based solely on the same-sex affair. Any such complaint would be dismissed for failure to state an offense or lack of probable cause.

No criminal liability attaches to the husband for the affair itself when it involves consenting adults. The same-sex partner likewise faces no criminal exposure under existing law.

Civil Remedies

The wife’s remedies are civil. The two primary actions are a petition for legal separation and a petition for declaration of nullity or annulment of marriage. These may be filed in the alternative in a single petition before the Family Court.

1. Petition for Legal Separation (Article 55, Family Code)

This is the most direct and commonly pursued remedy for post-marriage sexual infidelity.

Applicable grounds (Article 55):

Sexual infidelity or perversion (paragraph 8). A same-sex extramarital affair constitutes sexual infidelity because it violates the essential marital obligation of fidelity.
Lesbianism or homosexuality of the respondent (paragraph 6). Evidence of ongoing same-sex relations may establish homosexuality of the husband.

The petition is filed in the Family Court of the province or city where the petitioner resides. The marriage certificate, proof of the affair, and other supporting documents must be attached. Proof may consist of text messages, emails, social-media records, photographs, witness statements, or admissions. Evidence must be obtained lawfully; illegally obtained evidence risks exclusion and possible counterclaims.

Prescription and bars (Articles 56 and 57): The action prescribes five years from the occurrence of the cause. It is barred by condonation, consent, connivance, or reconciliation between the spouses.

Effects of a decree of legal separation (Article 63):

The spouses live separately, but the marriage bond is not severed.
The absolute community of property or conjugal partnership of gains is dissolved and liquidated. The offending spouse forfeits any share in the net profits earned by the community or partnership.
Custody of minor children is determined according to the best interest of the child. The sexual orientation of a parent is not, by itself, a disqualifying factor; the court focuses on the child’s welfare, stability, and moral and emotional development.
The innocent spouse is entitled to support from the guilty spouse.
The guilty spouse is disqualified from intestate succession to the innocent spouse’s estate, and any testamentary provision in favor of the guilty spouse may be revoked by the innocent spouse.
The court may award moral damages, exemplary damages, and attorney’s fees to the innocent spouse upon proof of mental anguish, social humiliation, or besmirched reputation caused by the infidelity.

2. Petition for Declaration of Nullity of Marriage on the Ground of Psychological Incapacity (Article 36, Family Code)

A marriage is void from the beginning if either party was psychologically incapacitated at the time of celebration to comply with the essential marital obligations of marriage, even if the incapacity becomes manifest only later.

A same-sex affair may serve as evidence of psychological incapacity when it demonstrates a grave, incurable, and juridically antecedent condition—such as a deep-seated homosexual orientation or related personality structure—that prevents the husband from fulfilling the obligations of fidelity, exclusivity, and the establishment of a conjugal family. Mere post-marriage infidelity or discovery of homosexuality is insufficient; the incapacity must be shown to have existed at the inception of the marriage.

Proof requires clear and convincing evidence, typically including expert testimony from a clinical psychologist or psychiatrist. The condition must be grave, permanent or incurable, and rooted before or at the time of the wedding. Success is fact-specific and more difficult to obtain than legal separation.

If granted, the marriage is declared void ab initio. Both parties may remarry. Children conceived or born before the declaration remain legitimate. Property relations are liquidated under the rules applicable to void marriages, with possible forfeiture if bad faith is established.

3. Annulment of Marriage on the Ground of Fraud – Concealment of Homosexuality (Articles 45(3) and 46(4), Family Code)

A marriage is voidable if consent was obtained by fraud. Article 46(4) expressly provides that concealment of homosexuality or lesbianism existing at the time of the marriage constitutes fraud.

If the husband was homosexual before the marriage and deliberately concealed this fact, and the wife can prove she would not have married had she known, the marriage may be annulled. The same-sex affair supplies corroborative evidence that the homosexuality pre-existed the marriage.

The action must be filed within five years from discovery of the fraud. It is barred if the wife, after discovery, freely cohabited with the husband as husband and wife.

Effects are similar to those of a declaration of nullity: the marriage is annulled, property is liquidated, children remain legitimate, and the parties may remarry. Bad faith in the concealment may affect property division.

Additional or Ancillary Remedies

Protection orders under Republic Act No. 9262 (Anti-Violence Against Women and Their Children Act): If the affair is accompanied by acts causing the wife mental or emotional suffering—such as public humiliation, harassment, stalking, or economic abuse—the wife may apply for a Barangay Protection Order, Temporary Protection Order, or Permanent Protection Order. Mere infidelity without additional abusive conduct usually does not meet the threshold for psychological violence under RA 9262.

Claim for damages: Moral damages (Civil Code, Articles 2217 and 2219) and exemplary damages may be awarded for the mental anguish, besmirched reputation, and social humiliation caused by the infidelity and related conduct. The claim may be included in the petition for legal separation, nullity, or annulment, or filed in a separate civil action before the appropriate court. Attorney’s fees and litigation expenses may also be recovered.

Accounting and reimbursement: If conjugal or community funds were used to support the affair, the wife may demand an accounting and reimbursement during property liquidation in any of the above proceedings.

Procedural and Evidentiary Notes

All actions involving marriage and family relations fall under the exclusive jurisdiction of the Family Courts. Proceedings are confidential. The court may refer the parties to mediation or counseling. The best interest of any common children remains the overriding consideration in custody, support, and visitation determinations. Sexual orientation alone does not determine custody; evidence must show actual impact on the child’s welfare.

Evidence of the affair must be competent and relevant. Communications, photographs, and admissions are commonly used. Private investigation is permissible if conducted lawfully.

The choice among legal separation, declaration of nullity, and annulment depends on the facts: whether the homosexuality pre-existed and was concealed (favoring annulment), whether it constitutes psychological incapacity (favoring nullity), or whether the infidelity occurred after a valid marriage (favoring legal separation). These actions may be pleaded in the alternative.

The wife should act promptly within the applicable prescriptive periods and avoid any conduct that could be construed as condonation or reconciliation, which would bar the action for legal separation.