I. Introduction

In the Philippines, falsely accusing a person of infidelity—whether adultery (committed by a married woman) or concubinage (committed by a married man)—constitutes defamation because it imputes the commission of a crime punishable under Articles 333 and 334 of the Revised Penal Code (RPC). Such accusations directly attack the honor, dignity, and reputation of the accused person and are considered defamatory per se. The law treats these imputations seriously because adultery and concubinage remain criminal offenses, and the false accusation tends to expose the victim to public hatred, contempt, ridicule, or shame.

Defamation in this context may be prosecuted as criminal libel (written or published), oral slander, or cyberlibel (online). Civil damages are almost always awarded in successful cases, and moral damages are presumptively suffered due to the inherently dishonorable nature of the imputation.

II. Criminal Defamation Under the Revised Penal Code

A. Definition of Libel (Article 353, RPC)

Libel is a public and malicious imputation of:

A crime;
A vice or defect, real or imaginary; or
Any act, omission, condition, status, or circumstance tending to cause dishonor, discredit, or contempt.

A false accusation of infidelity satisfies the first and third categories simultaneously: it imputes a crime (adultery/concubinage) and a moral vice (sexual immorality).

B. Elements That Must Be Proven Beyond Reasonable Doubt

Allegation of a discreditable act (infidelity);
Publication or communication to a third person;
Identifiability of the victim (need not be by name; sufficient if third persons can identify);
Existence of malice (presumed when the imputation is defamatory per se, as in this case).

C. Modes of Commission

Written libel (Article 355): Through writing, print, social media posts, private messages shown to others, letters, e-mails, blogs, etc.
Oral defamation/slander (Article 358): Spoken words, whether face-to-face or via voice call, livestream, or recorded audio shared with others.

D. Classification of Oral Defamation

Grave slander: When the accusation imputes a crime or is of a serious and insulting nature (e.g., calling a married woman “adulteress,” “kabit,” or saying a husband “keeps a mistress”).
Simple slander: Mere insulting words without imputing a crime (rarely applies to infidelity accusations).

Jurisprudence consistently holds that accusing a married person of adultery or concubinage constitutes grave slander (People v. Guhit, G.R. No. L-4054, 1951; Balite v. People, G.R. No. 213935, 2017).

E. Penalties

Written libel: Prisión correccional in its minimum and medium periods (6 months and 1 day to 4 years and 2 months) or a fine ranging from ₱200 to ₱6,000, or both.
Grave oral slander: Arresto mayor in its maximum period to prisión correccional in its minimum period (4 months and 1 day to 2 years and 4 months).
Simple slander: Arresto menor or fine not exceeding ₱200.

III. Cyberlibel Under Republic Act No. 10175 (Cybercrime Prevention Act of 2012)

The Supreme Court in Disini v. Secretary of Justice (G.R. No. 203335, February 11, 2014) upheld the constitutionality of Section 4(c)(4) on cyberlibel but struck down the “real-time collection of traffic data” and “takedown” provisions.

Key rulings:

Online libel is committed when the false accusation is posted on Facebook, Twitter/X, Instagram, TikTok, Viber group chats, Messenger threads shown to others, or any platform accessible to third persons.
One single post constitutes one count of cyberlibel, but each repost or share by others may constitute separate offenses by the reposter/sharer.
The penalty is one degree higher than ordinary libel: Prisión mayor (6 years and 1 day to 12 years).
Prescription period: 15 years (Act No. 3326 as amended by RA 10175).

Even private or “close friends only” posts can constitute publication if at least one third person had access (Villar v. People, G.R. No. 249700, 2022, involving a “friends only” Facebook post).

IV. Civil Liability (Independent Civil Action)

Defamation gives rise to a separate civil action for damages under Articles 19, 20, 21, 26, 32, 33, 34, and 2176 of the Civil Code.

Available Damages

Moral damages: Presumed in defamation per se (no need to prove actual suffering). Awards typically range from ₱100,000 to ₱1,000,000+ depending on the victim’s social standing and extent of publication.
Exemplary damages: To deter similar acts, especially when malice is evident.
Temperate damages: When some pecuniary loss is shown but amount cannot be proven with certainty.
Attorney’s fees and litigation expenses.

Landmark awards:

In MVRS Publications v. Islamic Da’wah Council (2003), moral damages were denied for a juridical person, but natural persons routinely recover.
In Filipino Broadcasting v. Ago Medical Center (2005), ₱300,000 moral damages for libelous radio broadcast.
Recent cyberlibel cases (2020–2025) have awarded ₱500,000–₱2,000,000 moral damages when the false accusation of infidelity went viral.

The civil action may be filed separately and does not depend on the outcome of the criminal case (Article 33, Civil Code).

V. Defenses Available to the Accused

Truth of the imputation + good motives and justifiable ends (Article 361, RPC).
→ Mere truth is not enough; the accuser must prove the infidelity actually occurred and that the accusation was made for a justifiable purpose (e.g., protecting legitimate interest).
→ If the accusation is false, this defense automatically fails.
Absolute privileged communication (e.g., statements in judicial proceedings, congressional hearings).
→ Does not apply to social media posts or private conversations.
Qualified privileged communication (e.g., fair commentary on matters of public interest).
→ Rarely applies to private sexual conduct unless the person is a public figure and the accusation relates to fitness for office.
Lack of identifiability or publication.
→ Almost never successful when names or recognizable details are used.

VI. Special Considerations

A. Accusations Between Spouses or Former Spouses

Spouses or ex-partners can sue each other for defamation. The marital disqualification rule (Rule 130, Section 22, Rules of Court) only prevents compulsory testimony, not the filing of the complaint itself.
Common in legal separation or annulment cases where one party parades the other’s alleged infidelity on social media.

B. Accusations Against Unmarried Persons

Calling an unmarried woman “kabit,” “mistress,” or “malandi” is still libelous/slanderous because it imputes moral turpitude or a vice tending to cause dishonor, even if no crime is technically committed (U.S. v. Eguia, 1908; People v. Andrada, 1957).

C. Use of Indirect or Veiled Language

Terms such as “may iba,” “may kalaguyo,” “may kinakasama,” “may side chick,” or posting suggestive photos/memes are sufficient if third persons understand the reference (Figueroa v. People, G.R. No. 147406, 2008).

D. Prescription Periods

Ordinary libel/slander: 1 year from discovery/knowledge.
Cyberlibel: 15 years.

VII. Practical Remedies for Victims

File criminal complaint-affidavit with the Office of the City/Provincial Prosecutor.
Simultaneously or separately file civil complaint for damages with the Regional Trial Court.
Request preliminary investigation; subpoena phone records, screenshots, witnesses.
Seek issuance of Hold Departure Order if accused attempts to flee.
File petition for protection order under RA 9262 if the false accusation forms part of psychological violence (although RA 9262 primarily protects women and children, men may invoke analogous relief under the Anti-VAWC Act’s gender-neutral provisions as interpreted in recent jurisprudence).

VIII. Conclusion

False accusations of infidelity remain one of the most commonly prosecuted forms of defamation in the Philippines precisely because they strike at the core of personal honor in a predominantly conservative, family-oriented society. The law presumes malice, presumes injury, and imposes severe penalties—especially in the age of social media where a single post can ruin reputations overnight. Victims are strongly encouraged to pursue both criminal and civil remedies, as the courts have consistently awarded substantial damages while sending a clear message: baseless attacks on a person’s fidelity will not be tolerated.

Parties contemplating such accusations—whether out of anger, revenge, or jealousy—are well-advised to remember that the truth is a defense only when it is provable and made with good motives. Otherwise, the accuser risks imprisonment, crushing fines, and multimillion-peso civil liability.