1) The core idea: one fact can trigger multiple legal problems

If you are romantically involved with someone who is already married, the legal exposure in the Philippines usually clusters into two areas:

Sexual-relations crimes under the Revised Penal Code (RPC)
- Adultery (if the married partner is the wife)
- Concubinage (if the married partner is the husband)
Marriage-status crimes under the RPC / Family Code framework
- Bigamy (when a person marries again while a prior marriage legally exists)

These are separate. A person can face adultery/concubinage without bigamy, and bigamy without adultery/concubinage.

2) Bigamy (RPC Art. 349): the “second marriage while the first still exists” crime

A. What bigamy is

Bigamy is committed when a person:

has a first valid (or at least legally subsisting) marriage, and
contracts a second (or subsequent) marriage, and
the first marriage has not been legally dissolved (or the spouse not legally presumed dead under the Family Code).

Key point: In the Philippines, you cannot treat yourself as single just because you believe the first marriage is “void,” “ended,” or “dead in fact.” For remarriage purposes, Philippine law generally demands a court judgment before you remarry.

B. Who is usually criminally liable

Primary liability usually falls on the spouse who remarried (the one with the prior marriage).
The new spouse/partner is not automatically guilty of bigamy, but can face risk if prosecutors treat them as having knowingly helped (as an accomplice) in exceptional cases. In practice, bigamy cases overwhelmingly target the person who remarried.

C. What does not automatically protect the remarried spouse

Common situations that still carry bigamy risk:

“We were separated for years already.”
“My first marriage was void anyway.”
“I filed a nullity/annulment case later.”
“My first spouse agreed / gave permission.”
“My first spouse disappeared, so I remarried.” (Without a court declaration of presumptive death, this is high-risk.)

D. The safest “legal exits” before remarriage

To remarry without bigamy exposure, the person who is married typically needs one of these completed first:

Judicial declaration of nullity (for void marriages) final and executory
Annulment (voidable marriages) final and executory
Legal recognition of a valid foreign divorce (when applicable), plus recognition in Philippine court before relying on it
Judicial declaration of presumptive death (Family Code Art. 41) for a missing spouse, before remarriage

E. Typical evidence in bigamy cases

Marriage certificates (first and second)
Proof the first marriage was still existing at the time of the second
Records from the PSA / local civil registrar
Testimony establishing identity of the accused and fact of the second marriage ceremony

F. Common defenses (and how they actually work)

Defenses depend on which element is attacked:

No “first marriage” legally existed
- Example: the “marriage” never happened as a marriage in law (e.g., absence of essential requisites so severe that there was effectively no marriage to begin with).
- This defense is narrow and fact-specific.
First marriage was already legally ended before the second
- A final court judgment of nullity/annulment before the second marriage is the cleanest defense.
- Death of the spouse also ends the marriage, but proof must be solid.
Presumptive death was judicially declared before remarriage
- If the remarriage happened only after a valid court declaration of presumptive death, bigamy is generally avoided.
Mistake of law / “good faith”
- Generally weak for bigamy. Courts typically expect parties to follow the required judicial processes before remarriage.

G. Practical risk note for the unmarried partner (the “new” spouse)

Even if you are single, marrying someone who is still legally married can lead to:

Being pulled into an investigation and case as a witness or respondent
Expense, reputational harm, and immigration/record consequences
A void marriage on the civil side (your marriage itself is legally defective), with cascading property and child-status issues

3) Concubinage (RPC Art. 334): when the married partner is the husband

A. Concubinage is not “any affair”

Concubinage is not automatically committed by every married man who has sex outside marriage. The law penalizes specific circumstances, typically any of these:

He keeps a mistress in the conjugal dwelling; or
He cohabits with the mistress “in any other place”; or
He has sexual intercourse with her under scandalous circumstances.

Because of these qualifiers, concubinage can be harder to prove than adultery.

B. Who can be charged

The married man can be charged.
The woman may be charged as the concubine (with a penalty typically different from the husband’s).

C. Who can file / how prosecution starts (private-crime rules)

Concubinage is a private crime: it generally cannot proceed unless the offended spouse (the wife) files the complaint that starts the criminal action.

Important procedural features (commonly litigated):

The complaint must generally include both the husband and the alleged concubine.
Consent or pardon by the offended spouse can bar prosecution (facts matter; timing and proof matter).
If the spouses have reconciled and the offended spouse clearly forgave, that can become a major issue.

D. Penalties (high-level)

Concubinage penalties are generally less severe than adultery in statutory design, and the “concubine” penalty is different in kind from the husband’s. The exact penalty range depends on the statute’s text and application.

E. Common defenses

Failure to prove a qualifying circumstance
- Proof of a single private encounter is not automatically concubinage unless the law’s specific circumstances are met.
Identity and participation
- Challenging identification, location, cohabitation, “keeping,” or “scandalous circumstances.”
Procedural defects for private crimes
- No valid complaint by the offended spouse
- Failure to include both accused parties when required
- Evidence of prior consent/pardon/reconciliation that legally blocks the case
Lack of knowledge (for the alleged concubine)
- A claim that she did not know he was married may matter to culpability, depending on how the facts show intent and participation.

4) Adultery (RPC Art. 333): when the married partner is the wife

A. Adultery has a simpler structure than concubinage

Adultery is typically committed when:

A married woman has sexual intercourse with a man not her husband; and
The man participates (commonly discussed alongside the idea that he knew she was married).

Unlike concubinage, adultery does not require “cohabitation,” “keeping,” or “scandal.”

B. Who can file (private-crime rules)

Adultery is also a private crime: it generally proceeds only upon complaint of the offended spouse (the husband), and typically requires inclusion of both participants.

C. Common defenses

No proof of sexual intercourse
- Suspicion, messages, or hotel sightings may be suggestive but not always enough on their own.
Procedural defects (private-crime requirements)
- No proper complaint by the offended spouse
- Failure to include both accused parties when required
- Consent/pardon/reconciliation defenses where supported by facts
Knowledge / good faith issues for the male co-accused
- If the male participant plausibly did not know she was married, that can be a focal defense theory (highly fact-dependent).

5) The “unmarried third party” problem: what you risk if your partner is married

A. If you are dating (not marrying) a married person

You can still face criminal exposure as:

Paramour in adultery (if the married partner is the wife), or
Concubine in concubinage (if the married partner is the husband, and the statutory circumstances are met)

But your exposure depends on:

the gender/marital status of the married partner (adultery vs concubinage),
whether the offended spouse files the proper complaint (private crime),
and the quality of proof.

B. If you marry a person who is still married

The bigger structural harm is that:

the marriage is typically civilly defective/void, and
the married partner may be prosecuted for bigamy, with collateral consequences for you.

6) Civil-law fallout (Family Code and property/children consequences)

A. The relationship status can affect property rights

When a “marriage” is void (including because of bigamy), property relations can be complicated. Courts may apply rules that depend heavily on:

the parties’ good faith/bad faith,
who contributed money/property,
and whether the relationship falls under statutory provisions for unions without a valid marriage.

B. Child status and support

Children’s status (legitimate/illegitimate) and support rights depend on the legal framework governing the parents’ relationship and the applicable Family Code provisions. Regardless of legitimacy classification, support obligations for children are a serious and enforceable matter.

C. Legal separation, nullity, and related family cases

Infidelity (and the facts around it) often becomes evidence in:

legal separation cases (where relevant),
custody/visitation disputes,
support and protection order proceedings (depending on circumstances)

7) Evidence, privacy, and “self-help” that can backfire

People often try to gather proof of affairs or secret marriages. In the Philippines, evidence-gathering can create separate liabilities if done unlawfully, including:

recording private communications without legal basis (wiretapping concerns),
non-consensual photo/video capture in private settings (anti-voyeurism concerns),
hacking/unauthorized access to accounts (cybercrime concerns),
improper handling of personal data (data privacy concerns)

Even when your underlying claim is strong, illegally obtained or illegally gathered material can create major legal problems.

8) Procedural realities and leverage points

A. Private-crime gatekeeping (adultery/concubinage)

Because adultery and concubinage generally require the offended spouse’s complaint:

Many cases turn on standing, proper party, and pardon/consent issues.
If the offended spouse is unwilling or has clearly forgiven, the criminal path can collapse.

B. Bigamy is not a private crime

Bigamy is prosecuted as a public offense:

It does not depend on the offended spouse’s willingness in the same way.
Documentary records often make it easier to initiate and sustain.

9) Practical “risk map” for common scenarios

Scenario 1: You are single, dating a married man

Possible concubinage exposure for him (and for you) only if statutory qualifiers can be proven and the wife files properly.
Civil exposure: reputational harm, possible damages theories depending on facts (courts are cautious; outcomes vary).

Scenario 2: You are single, dating a married woman

Adultery exposure for both of you if the husband files properly and proof meets the threshold.

Scenario 3: Your married partner says “my first marriage is void,” and you plan to marry

High bigamy risk unless there is already a final court judgment (or another legally recognized termination) that restores capacity to remarry.

Scenario 4: The spouse has been missing for years

Remarriage without a judicial declaration of presumptive death is high-risk for bigamy.

Scenario 5: Foreign divorce is involved

Even if a divorce happened abroad, relying on it in the Philippines without proper judicial recognition can create capacity-to-remarry issues and bigamy risk, depending on citizenship and facts.

10) Summary of the strongest defenses by charge type

Bigamy

A legally effective end to the first marriage before the second marriage (final judgment, death, presumptive death order, properly recognized divorce where applicable)
No legally cognizable first marriage existed (rare, fact-dependent)
Attacking proof of identity or proof of contracting the second marriage

Adultery

No proof of sexual intercourse
Procedural defects (no valid complaint; improper inclusion; pardon/consent issues)
Knowledge/good faith issues for the co-accused man (fact-dependent)

Concubinage

No proof of statutory qualifying circumstances (no keeping in conjugal dwelling, no cohabitation, no scandalous circumstances)
Procedural defects and pardon/consent issues (private crime rules)
Identity/knowledge defenses for the alleged concubine (fact-dependent)

Legal-information notice

This article is general legal information in the Philippine context and does not replace advice tailored to specific facts, evidence, and local prosecutorial/court practice.