In the Philippines, infidelity is not merely a moral or civil issue; it is a criminal offense classified under the Revised Penal Code (RPC) as a "Crime Against Chastity." However, the law distinguishes between the acts committed by a wife and those committed by a husband through two distinct crimes: Adultery and Concubinage.
I. Legal Definitions
Adultery (Article 333, RPC)
Adultery is committed by any 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, even if the marriage is later declared void.
- The Accused: The married woman and her paramour.
- The Act: A single act of sexual intercourse is sufficient to constitute the crime.
Concubinage (Article 334, RPC)
Concubinage is committed by any husband who:
- Keeps a mistress in the conjugal dwelling;
- Has sexual intercourse under scandalous circumstances with a woman who is not his wife; or
- Cohabits with her in any other place.
- The Accused: The married man and his concubine.
- The Act: Unlike adultery, a single act of intercourse is generally insufficient. The prosecution must prove one of the three specific conditions mentioned above.
II. Essential Requirements for Filing
To initiate a criminal complaint for Adultery or Concubinage, the following requirements and conditions must be met:
1. The Proper Party (Private Crime)
Under the Rules of Court, these are "private crimes." This means the criminal action cannot be prosecuted except upon a complaint filed by the offended spouse.
- The state cannot initiate the case on its own.
- If the offended spouse has died or is incapacitated, the right to file generally does not transfer to relatives in the same way as public crimes.
2. Requirement of "Total Prosecution"
The offended spouse must include both the guilty spouse and the paramour/concubine in the complaint, if both are alive. You cannot choose to sue only the third party and spare your spouse, or vice versa.
3. Evidentiary Requirements
Because these are criminal cases, the standard of proof is proof beyond reasonable doubt.
- Adultery: Direct evidence of sexual intercourse is often difficult to obtain. Therefore, circumstantial evidence—such as photographs, videos, witness testimonies, or love letters—that leads to an unavoidable conclusion of carnal knowledge is required.
- Concubinage: Evidence must specifically target one of the three modalities. For "scandalous circumstances," witnesses must testify to the public nature of the affair. For "cohabitation," proof of a shared household or a "live-in" arrangement is necessary.
III. Grounds for Dismissal or Defense
The law provides specific instances where a case may be barred or dismissed:
- Consent: If the offended spouse agreed to the infidelity beforehand.
- Pardon: If the offended spouse has expressly or impliedly (e.g., continued cohabitation after discovery) pardoned the guilty parties.
- Affidavit of Desistance: If the offended spouse formally withdraws the complaint, though the court must still approve the dismissal.
IV. Comparison of Penalties
The Philippine legal system currently maintains a disparity in the penalties and elements for these two crimes:
| Feature | Adultery | Concubinage |
|---|---|---|
| Standard | Any sexual intercourse. | Specific conditions (Mistress in home, scandal, or cohabitation). |
| Penalty for Spouse | Prision correccional (higher imprisonment). | Prision correccional in its minimum and medium periods (lower imprisonment). |
| Penalty for Third Party | Same as the wife. | Destierro (banishment from a specific radius), not imprisonment. |
V. Procedural Steps
- Filing the Complaint: The offended spouse must execute a sworn Complaint-Affidavit, usually filed before the Office of the City or Provincial Prosecutor.
- Preliminary Investigation: The Prosecutor determines if there is "probable cause" to believe the crime was committed.
- Filing of Information: If probable cause is found, the Prosecutor files the "Information" (the formal charge) in court.
- Arrest and Trial: The court issues a warrant of arrest. The accused may post bail. The trial then proceeds to determine guilt beyond reasonable doubt.