In the Philippine legal system, "infidelity" is not a standalone crime but is prosecuted under specific provisions of the Revised Penal Code (RPC) and special laws. When these personal conflicts spill over into social media, they often intersect with Republic Act No. 10175, or the Cybercrime Prevention Act of 2012.

1. Criminal Charges for Infidelity

Infidelity is criminalized differently depending on the gender of the spouse committed the act and the specific circumstances of the relationship.

Adultery (Article 333, RPC)

Definition: 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 her to be married.
Key Requirement: Proof of sexual intercourse is necessary. Each individual act of intercourse constitutes a separate crime.
Parties Charged: Both the wife and the paramour must be charged together.

Concubinage (Article 334, RPC)

Definition: Committed by a married man who:

Keeps a mistress in the conjugal dwelling;
Has sexual intercourse under scandalous circumstances; or
Cohabits with her in any other place.

Distinction: The evidentiary bar for concubinage is higher than adultery. Simple sexual intercourse is not enough; it requires "keeping," "cohabitation," or "scandalous circumstances."

Psychological Violence (R.A. 9262)

Under the Anti-Violence Against Women and Their Children Act (VAWC), marital infidelity can be classified as a form of psychological violence.

The Supreme Court has ruled (e.g., AAA vs. BBB) that the mental or emotional anguish caused to a wife by her husband’s infidelity—even if the infidelity happened abroad—can be prosecuted in the Philippines if the victim suffers the effects (the mental anguish) locally.

2. Cyber Libel (R.A. 10175)

When an aggrieved spouse posts about the infidelity online (Facebook, X, Instagram, etc.) to shame the parties involved, they risk being sued for Cyber Libel.

Elements of Cyber Libel

For a charge to prosper, four elements must be present:

Defamatory Imputation: An allegation of a crime, vice, or defect that tends to cause dishonor or contempt.
Publicity: The post must be viewable by a third person. On social media, even "Friends Only" posts can meet this criteria.
Malice: The intent to harm the reputation of the subject. In Philippine law, if the post is defamatory, malice is often presumed (Malice in Law).
Identifiability: A third person must be able to recognize who is being talked about, even if names are not explicitly mentioned.

The "Truth" Defense

In the Philippines, "truth" is not an absolute defense in libel. Even if the infidelity is true, the poster can still be liable if there was no good intention or justifiable motive for making the information public. Publicly shaming a "kabit" (paramour) out of revenge often qualifies as malice.

3. The Safe Spaces Act (R.A. 11313)

Commonly known as the "Bawal Bastos" Law, this act covers Gender-Based Online Sexual Harassment.

This includes uploading or sharing photos or videos without consent with the intent to shame or humiliate.
Using "slat-shaming" language or harassing the paramour online can lead to imprisonment and heavy fines under this law, separate from Cyber Libel.

4. Key Procedural Facts

The "Pardon" Rule

In Adultery and Concubinage, if the offended spouse has consented to the infidelity or pardoned the offender (either expressly or impliedly), a criminal case can no longer be filed.

Prescription Periods

Adultery/Concubinage: These are "private crimes" and must be prosecuted by the offended spouse. They prescribe (expire) in 20 years, but practically, the evidence becomes harder to secure over time.
Cyber Libel: There has been historical debate on the prescription period (ranging from 1 year to 15 years), but current jurisprudence often leans toward a longer period due to the nature of the Cybercrime Law.

Comparison Table: Penalties

Crime	Minimum Penalty	Maximum Penalty
Adultery	2 years, 4 months	6 years
Concubinage	6 months (for husband)	4 years (for husband)
Cyber Libel	6 years, 1 day	12 years
VAWC (Psych)	6 years, 1 day	12 years

Note: The penalty for Cyber Libel is one degree higher than traditional libel under the RPC, making it a non-bailable offense in many jurisdictions depending on the specific duration of the sentence sought.